I think Thorongil meant to "the more important question is not what objects are, but why they exist." We are not responsible for the reason of a thing's existence (excluding the obvious man-made stuff). — Michael

Oh well, why ask why? What reason do we have to suppose things have a reason for existing? We can explain the mechanics for how they came to exist (to a point), but not give a reason in terms of purpose.

I don't think even that would work, as it could be that the "real" world operates according to different physical laws, and the ones we're familiar with are only the laws of our simulation. — Michael

Like maybe in the real world P=NP, but not our simulation?

But it seems like if you could show that it's impossible to construct a simulation in our world, then the basis for the simulation argument is undermined (because what do you mean by our world being simulated?). However, that sounds related to Putnam's argument against being able to make a radically skeptical realist assertion.

I don't think so. — Thorongil

How could the why not be up to us? Are you in personal contact with God or aliens? What sort of BS have they been feeding you?

I suppose if you could show that we can't be brains in a vat even if metaphysical realism is the case then you can argue that realism doesn't entail radical skepticism, and so refute Putnam's argument. — Michael

Maybe so, but t's hard to see how metaphysical realism doesn't entail the possibility of some form of radical skepticism, even though I am a realist.

Even if BIVs aren't tenable, a Matrix, Star Trek holodeck or Boltzmann Brain scenario might be. You'd have to show that such a simulation isn't physically possible, and everything I've read leads me to believe that it is possible to compute a convingly realistic world. And if you're born into that world, you wouldn't know what was unrealistic anyway (relative to the actual physical world).

One possible answer to the Fermi Paradox is that advanced aliens are feeding us a simulated universe that looks empty. In that case, we'd only be wrong about the wider universe, not matters inside the solar system (extra solar light would be simulated to fool us).

hat classic scientific theories assume that things exist unperceived is a kind of bias of those theories. It isn't needed to make sense of them, so far as I can tell. It just requires imagination and the willingness to entertain views which are different to what we ordinarily accept. — PossibleAaran

Not sure how you can accept chemistry as scientifically valid without conceding the existence of the atomic world which makes the periodic table what it is. Same with the germ theory of disease, cell biology or neuroscience.

Sure, we have equipment that can make those things perceivable to us, but most of the time atoms, microbes and cells are unperceived. The molecules science says you are made might never have been perceived by anyone.

So the reason idealism is significant, is to remind us that knowledge is always conditional, dependent, and in some sense subjective. Not in the sense of there being simply no objective truth, but that there is no ultimately objective truth. — Wayfarer

But this conflates epistemology with ontology. Just because there is a process by which we come to know about the world doesn't mean the world is constituted of that process.

We can analogize this to modern astronomy where sophisticated telescopes feed data to software that produces results for astronomers to analyze. There is a process in constructing knowledge of the cosmos.

But that doesn't mean the cosmos is therefore constructed by telescopes and software! It's a fallacious move to make. This is where Stove's worst argument gets it right.

Again, this is the core problem with Idealism and phenomenalism as I see it: they want to keep their cake and eat it. They want to call what's happening in the present moment "experience", "perception", "observation", etc., etc., but they want to retain universal doubt. But if you're universally doubting, then you can't call what's happening right now "perception", "experience", "observation" etc in the first place. But then as soon as you accept those terms, you implicitly accept the physical backstory, so there's no place for universal doubt any more. — gurugeorge

That's a really excellent critique. It undermines much of the bite of the hardcore idealist means of arguing where it's just one experience followed by another and nothing can be said of what happens in between.

So, the belief that the coffee exists unperceived isn't one that can be reliably established by any method at all. It is like the belief that there is a unicorn on mars. — PossibleAaran

It isn't like a belief in a unicorn on mars at all. We do have good reasons for thinking objects exist unperceived:

1. They're still around when we do perceive them again.
2. They can undergo change in our absence.
3. They can influence things we do perceive.
4. The perceived world is dependant on the unperceived for being the way it is.
5. We have no reason to suppose that things stop existing when we're not around.

A unicorn on mars doesn't fit any of that. It's like saying we have no reason to think unperceived paper doesn't turn into a unicorn or teleport itself to Mars. Why must it not exist? Why not anything fanciful? We're not perceiving the paper, so it could be anything or anywhere in addition to not existing, logically speaking.

Why is your doubt fixated on non-existence instead of any of an infinite number of unperceived scenarios?

Yes; doubt requires justification, too. — Banno

Maybe you can bring that up on the unperceived things not existing thread? OP is looking for a reason not to doubt. He mentions the idealist Stace who argued that there is no reason for thinking that unperceived objects and events exist.

Indeed, habit, as Hume himself says; but it is a leap that reason cannot justify. — unenlightened

Why is reason defined as deductive logic? Seems that animals and humans rely heavily on inductive reasoning. Deductive is something we came up with rather recently, but our ancestors didn't use it to survive, communicate and utilize tools, etc.

What ground do you have for supposing that the sun will not rise tomorrow? — Banno

Nothing and we have no grounds for expecting things to happen for no reason, particularly when it comes to large, complex objects like the sun.

It's like asking how do we know the sun won't turn into a giant teapot tomorrow. We can't prove that it won't deductively, but we have nothing that says stars have a means of turning into teapots.

Mathematical equations are meaningless symbolics until observations are substituted for variables. — Rich

That's why I said the world could be depicted by math. E=MC^2 means that the amount of energy in certain amount of mass is equal to that mass times the speed of light squared. That applies to any matter/energy conversion across space and time.

There is always some Mind (perspective) involved when observing and trying to understand or predict behavior(habits) in the universe. — Rich

Yes, but you're conflating how we know and represent things with the world itself. Are stars and galaxies dependent on telescopes and the software that processes those images? Of course not. That's just how modern astronomy gathers astronomical data.

Epistemology is not ontology.

I can see that the paper existed when the camera took its picture, but does the paper exist now? The camera is nothing more than an extension of the times at which I can view the paper; it cannot show that the paper exists unviewed tout court — PossibleAaran

What if you had a camera take a picture of the paper every nanosecond while it's in the drawer, and send that image to be processed by some software elsewhere. If the software sees that the image is a paper, it wires a cent to your bank account.

You step out of the room and check your account a minute later and notice that it's gone up by millions of dollars. The paper, drawer, camera and software doing paper detection and money wiring are all unperceived, but your bank account gains a lot of money very quickly, which if you calculated the time it took for the image to be taken, sent, processed and your count accredited would come out to having a picture taken every nanosecond by that camera with that software on the server it runs on at that time with your internet connection (the images would be buffered as they arrived, waiting for the software to check them).

Would that not establish the existence of the unperceived paper, at least every nanosecond (or however many nanoseconds got turned into cents)?

The point is that the perceived world is influenced by the unperceived world. You can't just say the rest of the world only exists when perceived given the way the world hangs together. The reason being that the perceived part of the world is being influenced by the unperceived world in countless ways.

You're not familiar with cosmology, are you? — Metaphysician Undercover

I'm familiar with the speed of light being a constant against which measurements of length and time are made across different inertial frames. Note the taking into account different observers making measurements.

I'm also aware that GR accounts for gravity across the cosmos and throughout time.

e cannot produce a mathematical model of the universe which is independent from perspective. This is one of the key things that special relativity demonstrates to us. — Metaphysician Undercover

Pretty sure you're wrong about this.

We already agreed that the Idealist can posit (a) a car hurtling towards him when he sees it, and (b) a car hitting him in the back when he feels it. He need not postulate a car which exists in the interim, when he is not seeing or feeling a car at all, nor need he postulate that these three are 'the same' car. — PossibleAaran

But he might not feel anything as well. Experience just ends.

Why is there the concretely, fundamentally, objectively existent world that you believe in? — Michael Ossipoff

Ask a cosmologist. In general, why anything exists is a question everyone has a problem answering.

As I've said, I can't prove that the Materialist's concretely, fundamentally, objectively existent world doesn't superfluously exist, as an unnecessary brute-fact, an unverifiable and unfalsifiable proposition, along side of, and duplicating the events and relations of, the complex system of inter-referring abstract if-then facts about hypotheticals that i've been referring to. — Michael Ossipoff

And I wouldn't agree with that depiction of materialism.

Without a temporal perspective there is no such thing as the way that the world is. That's why it's a senseless questi, on to ask about the way that the world would be without an observer. Without an observer there is no such thing as the way that the world is. — Metaphysician Undercover

And I explained how I disagree with that, given that we can depict the world mathematically without a perspective, and given that our lack of a ability to picture a perspectiveless world does not necessitate the world can't be that way.

Does it make sense to think that a brain can represent to itself the criteria of its own existence? — sime

Sure, why not? The brain recognizes that it has a limited lifespan. It sees that it's made of the same biological stuff that everything else is, which means it will die.

All i mean to say is that if subjective idealists are understood to be verificationists in the strongest possible sense, then it makes no sense for them to speak of an absence of experience when it comes to their own experience. — sime

Would such verificationism also commit one to not being able to speak of past experiences except as memories now, or future experiences except as anticipation now?

IOW, all that could be known to exist is the solipsist's perception right now.

In conclusion the subjective idealist is a solipsist who cannot make sense of the statement "I am mortal". Yet why should this be absurd by your criteria? After all, the solipsist is not only against holding views that he cannot disprove, he is even against attributing meaning to such views. — sime

The solipsist thinks they are eternal and their experience will never end? How is that not completely unfounded?

The Idealist can posit the two items experienced - the car that you see and the car that hits you- and say that usually seeing one is followed by feeling the other. He need not posit the existence of a car that exists in between these two states, nor need he say that all three are "the same" car.

The same with the piano. The Idealist says that there is the piano that you see falling towards you, and there is the piano that strikes you in the head, but he need not postulate another piano which exists when you aren't perceiving it, nor that all three are "the same" piano. — PossibleAaran

The idealist can make this move, but there is also the possibility that experience just ceases. Other people will infer that the falling piano or oncoming car killed you. The examiner might say poor sap didn't even feel it.

So the idealist has to include the possibility that not looking will result in no longer experiencing, for no reason at all, since there is no unperceived death event.

There is something to be said against views which we can't disprove but are absurd. Let's say that instead not existing, the piano turns into a pink elephant that squashes you, but then turns back into a piano when people find your body. Can you disprove that possibility? No, but it's silly and absurd on the face of it.

I can feel the oxygen as I inhale it, can I not? If you say "no. You cannot tell from inhaling that what you inhale is oxygen molecules", then fair enough, but the existence of the molecules can be securely inferred from the perceptible properties of air. — PossibleAaran

There's a thousand different variants of this. Someone slips an odorless, tasteless poison into your drink when nobody else is looking. They leave the room.

Now the poison should cease to exist just like the paper, right? You drink from the chalice and next thing you know you're vomiting blood and being rushed to the emergency room where the doctor figures out what poison was used and counters it to save your life. So somehow that unperceived poison came back into existence.

Now if you can do away with experiences being causally connected to one another, and say that you there was no reason you went to the emergency room, then you can maintain your doubt.

I can't do that. I find it to be a reductio. Of course the poison, the paper, the piano, the train wheels, etc. all exist unperceived. That makes sense of why our experiences do seem to be causally connected in a way that papers remain in drawers when nobody's looking.

Close - but no cigar — Wayfarer

How many qualia can dance on the end of a cigar?

If the experiment had been performed in reality, which it hasn't, that might prove the existence of the fire in those contrived circumstances, but the existence of regular objects in regular circumstances would remain unproven. — PossibleAaran

Thought experiments are used in philosophy. And this one can be performed in the real world. But you can change it to an actual situation where there was a fire but nobody was aware of it, because they were asleep or it was in another part of the building, and they suffocated.

you employ the same tactic sometimes employed by Marchesk. That is, to answer my question by asking other questions in the hope that my original question then sounds ridiculous. — PossibleAaran

Well, it is ridiculous when taken to it's logical conclusion. If the paper in your drawer no longer exists unperceived, then the piano falling toward you no longer exists when you look away.

Because how can the unperceived world be of any threat?

incorrect. — Wayfarer

Humans are angels in animal bodies ???

-we exist (can't imagine a substantive dialogue between a being who believes he and the other exists and a being who believes his own self and/or the other does not exist); — WISDOMfromPO-MO

Well, the solipsist argues that others do not exist. And then the Buddhists and other like-minded folk say the self does not exist. Descartes can be criticized on the grounds that he assumed there was an I to the experience of having a doubt, given that he was supposed to be entertaining 100% radical doubt.

the symbol "1" represents a particular quantity; — WISDOMfromPO-MO

Or it exists platonically independent of any actual quantity.

words uttered aloud are associated with thoughts in the mind of the utterer and are not random sounds; — WISDOMfromPO-MO

Alternatively meaning does not exist in the head (semantic externalism), and language does not reference private states (Wittgenstein). You also have the behaviorists and the eliminative materialists.

The exchange of ideas is probably mostly referencing that essential core. — WISDOMfromPO-MO

An exchange of ideas happens, but what that entails is very much up for debate, as almost everything can be called into question or interpreted differently.

The title of this thread is an update: disagreement is real; but it exists in spite of everybody essentially being in agreement. — WISDOMfromPO-MO

I essentially disagree with this.

LOL, what absurdities some metaphysical standpoints commit adherents to! :s — Janus

Indeed. There were huge disputes over some of these absurd commitments back on the old site.

Something just occurred to me. Can you classify a visual experience as a perception if your perceptual system doesn't exist since nobody's perceiving it?

So, all the 'machinery' that we believe gives rise to perception, and that is never itself perceived during acts of perception, does not exist? — Janus

Apparently your eyes and brain don't exist when nobody's perceiving them, but you can still have a visual perception.

For example, Materialism doesn't hold up well in discussion. — Michael Ossipoff

I think it holds up pretty well. Trouble is when it comes to mind, at least consciousness. But that's a small part of the entire universe, so I'm not as sold on the hard problem as I used to be.

But, it is my understanding, nobody has ever observed any such "causing" happening. — WISDOMfromPO-MO

Seems awful like experience things causing other things all the time. Sometimes I'm wrong about what's causing what, and confuse correlation for causation.

So a person's story has a beginning (birth) but not an end? Appealing to reincarnation to continue experience is no better than appealing to heaven. Neither are demonstrable.

Does a fire continue to burn even when no one is looking? A critic of Stace had said that it must do so, because when you return to the fire after ten minutes, the wood has turned to ash, which is just what happens if you stay and watch the fire burn out. Stace pointed out that this argument assumes that the law of causation operates continuously through time, whether observed or unobserved, and this is obviously part of what needs to be proven. — PossibleAaran

Let's say you're shut in a vacuum sealed room with a fire. Both you and the fire are consuming the limited oxygen in the room.

Then a partition is put between you and the fire that blocks your from seeing, hearing or smelling the fire. It ceases to exist as a perception. Furthermore, there is a timer that will let you out before your run out of air, but only if the fire on the other side of the partition is no longer consuming air.

What happens? Do you survive or does your air run out? How would Stace answer that?

And there's many alternatives to this like introducing a poisonous gas you can't perceive or emptying the oxygen from the room, all setup to be automated with nobody else around.

And really, why would the question of needing air come up at all? Why would you die of needing something (oxygen) you can't perceive?

The hiker didn't see the rock, but did any body else see it? If so, then the example is compatible with things only existing when perceived. If nobody saw the rock hit the hiker, not even the hiker (perhaps he was asleep), then how can anybody say with any degree of reliability that the rock actually did hit him? This hasn't been explained. — PossibleAaran

If you found a flattened hiker who had camped out next to rock face, then it's possible they didn't see or hear the falling rock. If it crushed them quickly enough, they may not have felt it either.

In that case, how could a non-existent rock do that? Or to put it into idealist terms:

How do we connect a rock we perceive to have crushed a human being with the cause of that human's death?

We can do it with realist language quite easily. But the idealist can't reference unperceived objects. We can't even reference the sleeping human here, because they might be unconsious, and without another perceiver, non-existent.

So you end up with the silliness that a non-existent rock crushed a non-existent human resulting in a perceived corpse and rock. That is, if things go out of existence when not perceived, and pop back into existence when perceived.

To go full subjective idealist mode, you just have a crushed corpse for no reason at all, where friends and family who identify the corpse with someone previously known will no longer experience interacting with that person as a living human. You get to avoid the stuff going in and out of existence, but then experience has these gaps to it and experiences happen without cause.

IOW, you ditch inference, and with it, explanations of any sort that aren't strictly deductive. You just have one experience following another for no rhyme or reason.

Wouldn't it be neat, if, say, a piano was falling down towards you, and you could look away, et voilà, the piano would no longer exist? — jorndoe

Exactly. If you look away from a falling rock, does it cease to exist until it crushes you, and then goes back to not existing once you die? What if you don't have time to experience the crushing? Does the non-existent heavy object not cause you to cease to exist?

In the end, we have to face the fact that this question, "does anything exist if unperceived", really doesn't make any sense at all, because "to exist" refers to how we perceive things. — Metaphysician Undercover

I think this fundamentally confuses how we come to know about the world with the way the world is itself. Just because we can't get outside ourselves to imagine exactly how the world is without us observing it does not entail that the world cannot exist without us perceiving it.

It can simply be a limitation on human imagination. But even then, we do possess powerful abstraction capabilities so that we can model the universe mathematically without any observer. We do have a theory of general relativity that deals with that.

But you’re still speaking from a realist perspective - whether scientific or not. — Wayfarer

Well, Berkley had the same sort of perspective in that he didn't saysay the light bouncing off a flower into your eye is an interpretive act. Rather, the omni-observer, God, is around to keep the rest of the world there as we would have perceived it.

By idealism you mean the Kantian variety where what is perceived might be entirely different than what caused the perception.

ur knowledge and experience is actually constituted, made up of different facets, all of which come into play when we see ‘the object’. And they are therefore constitutive of whatever we know of reality. That’s the sense in which reality is ‘dependent on perception’. — Wayfarer

But if you don't want to this to collapse into skepticism, you have to allow that our perceptual facilities do provide some accurate information about how things really are.

Why would we have eyes to see if what is seen isn't what's really there? That doesn't mean our senses gives us a completely accurate view of the world. They don't (and sometimes they mislead us). But you don't have to go all the way to the other extreme and say we can't know anything about the external world, trapping us inside the veil of perception (and interpretation).

Either science can be done on the world despite our perceptual limitations, or the ancients skeptics were right. I think given the huge success of science that the skeptics were premature in doubting so thoroughly.

But for those who haven't been 'through the looking glass', the question can only be dealt with from the perspective of scientific realism. — Wayfarer

I'm asking whether it's coherent to think that only the thing I'm experiencing right now exists given how that thing or part of the world is interdependent with the world in all sorts of ways. This also applies to me. I see, but what about the eyes I see with which I'm not perceiving?

You don't even need to bring science in to the equation. You can just note the interdependence of everything in the world from a phenomenal point of view.