This by the way is how to understand Kant's distinction between 'discursive' and 'intellectual' intuition: Kant's theory of the in-itself has nothing to do with the vulgar idea that there is a world that is 'beyond' perception in the sense that it has perceptual qualities that we cannot know. Rather, the in-itself is aperceptual, it has qualities which have nothing to do with perception, and that is why it will remain a 'thing-in-itself'. It is not that there are parts of the world that are 'beyond knowledge', as if a superior, non-human, or divine knowledge could grasp it, but that the very idea of knowledge is no longer applicable to certain aspects of the world, that is is a simple 'category error' to say we can know such and such beyond our experience of it. This is why Kant remained an empirical realist no less than he was a 'transcendental idealist'). — StreetlightX

That's very interesting, but I have a hard time reconciling it with ontological considerations. So if I adopt scientific realism, and I'm wondering about the nature of black holes, then is there something about black holes which can't be known? That we can't say at all what black holes are, independent of our astronomical experiences?

Such that advances in theoretical physics about the interior of black holes will only ever be about black holes in relation to how we humans perceive and think about the world? That there is something apart from that which is what black holes are, but can't be understood by us, or even aliens (based on how the perceive and think), or our machine overlords in the future?

Is the nature of black holes inherently unknowable?

I always thought ontology is about what exists, whether that includes minds, material things, forms, etc. And maybe with the qualification of what fundamentally exists, such that the many categories of things can be reduced to the four elements, water, atoms in the void, instantiations of the forms, ideas in the mind, whatever.

So being in an ontological sense, without making any commitments, is just about what fundamentally exists. Are objects like houses part of one's ontology? Not for mereological nihilists. So a building doesn't exist, ontologically speaking, for a mereological nihilist. It has no being. For an idealist, a building exists as a perception. A panpsychist, though, would say that a building is something that has it's own experiences.

But being might differ for existentialists, whose overriding philosophical concern is the nature of human life, and not what a building is.

Who the brain makes us out to be is dependent on the body that we are. — Bitter Crank

Agreed, very good post. Silicon Marchesk will not feel the same fatigue, hunger, thirst, cravings, kinesthesia, etc. Silicon Marchesk probably won't be subjected to the same sort of moods, being devoid of chemical influence. He won't be able to get drunk or high, or have a sugar rush, etc. His body image will quite different hooked up to a robot. Uploaded minds won't be the same without a meat wrapper.

People like Ray Kurzweil are a little too eager to leave the flesh behind. We don't know to what extent an emulated mind is going to deviate from its meat twin. I kind of suspect that an uploaded human mind would end up acting insane. It's interesting, though, how much popular scifi presents scenarios where people switch bodies or get uploaded into a computer, and they still act like their old personalities, as if the body is just a container for the mind, waiting the right tech to make the switch.

I suspect this all goes back to the Greeks, who came up with the idea of an immaterial soul, separate from the body, which influenced Christianity and Western philosophy. Also, the idea that the body is inferior to the mind, something to be abstracted away from to achieve purity of thought.

Are you your body, or are you something apart from your body? — Bitter Crank

I'm my body, and embodied cognition is largely correct, but ...

The cells of a nematode worm have been fully mapped, including its nervous system. That mapping has been emulated in a Lego Mindstorm robot, which is able to move around a room and avoid obstacles, just based on the emulated worm nervous system, with however they did the feedback from the robot sensors.

IOW, the robot wasn't programmed to move about or avoid walls and what not. That's the worm neural connection doing that. The people involved in the project even said they don't understand how the connectome works.

Which raises the question of whether if a few decades from now, when we have enormous computing power available, and if and when the human brain is fully mapped, can we do the same for a person?

What then?

Why are you conflating these things? — StreetlightX

So your point is that ontology is the destination, not the starting point, otherwise you end up with intractable disagreements.

I

What kind of thing is X such that it can even be spoken about in terms of an inside and an outside to begin with, or a beyond or not-beyond at all? — StreetlightX

I take it that on the account of realism, X is whatever makes up the world regardless of whether we know or perceive it. That could be ordinary objects, matter, information, math, some neutral stuff, whatever. But typically, it's the stuff of physics.

For idealism, it is either the various experiences we have (or any mind has), or the fundamental categories of thought for Kantians which structure or experiences, such as space and time.

I understand the fundamental crux of the debate to be whether man, or some kind of mind, is the measure of what exists, or whether what exists has it's own structure independent of what anyone thinks or experiences.

So for a scientific realist, The Big Bang, star formation, evolution, continental drift, etc. happened regardless of what we think about it, and it gave rise to us, incidentally. So our thinking should conform to how things went down, as best it can.

I take the debate as meaningful in the same way Meillassoux does, in that if idealism is the case, then we can't really mean that there were dinosaurs before us leading up to us. Instead we have to mean that it appears to us humans as if there were these creatures walking the world before us, and something, likely a large rock or ball of ice, killed most of them off, allowing for our small, furry ancestors to get on with it, and now we're here.

But it only seems like that to us, because we're correlated to the world or our experiences based on how we think. That sort of thing is worrisome to me. It means our best scientific theories aren't true. They only appear to be, because of whatever epistemic standards we've adopted in the current age, which cold change (see any of the many Landru posts about this in the previous forum).

What i'm saying is that it's a challenge along the lines of illusion or hallucination, because it potentially breaks down the difference between veridical perception and internal experiences. Difference not in veracity, but kind of experience, or where it's taking place, or how it's been generated. Meaning, it's a challenge to account for direct perception.

would have thought the fundamental issue of schizophrenia was the ability to recognise one's thoughts and internal states as being one's own. Hence 'a voice told me to do it'. What appears to be lacking is the integrative facility, i.e. the facility that integrates different thoughts, sensations, perceptions and judgements into a coherent whole; hence the popular (but frowned-upon) expression 'split personality' — Wayfarer

Sure, but the interesting thing is losing the ability to discriminate what's going on in your head from some potential outside source, so that it seems like the TV is putting thoughts into your head, or you're hearing or seeing something out there which other people don't.

It's as if a normal functioning brain needs to discriminate between the source from external and internal, and if it doesn't then your perception of reality breaks down and the two overlap. That sounds like a potential challenge to direct realism.

My dreams, hallucinations etc. are nothing like experiences of real things. — Terrapin Station

I recall reading something interesting about Schizophrenia were schizophrenics lose the ability to tell the difference between what's in their heads, and what they're perceiving. Apparently, the brain flags stuff that's generated internally.

That's highly suggestive, if it's true. I did come across that article in Scientific American or Nature years ago.

Wrong. A realist believes, at minimum, that some real things exist, at least at some times. That doesn't require believing that things continue to exist when no one sees them. — Terrapin Station

You're not a realist if you don't believe that, because otherwise, your position is no different from anti-realism, as I'm sure Michael well tell you, or SEP, if you look. The central point of realism is mind-independence.

That's like saying that some cards are hearts and some clubs, so you need something more to justify that some cards are hearts. — Terrapin Station

No, it's like saying I directly experience hearts, but sometimes dream of, hallucinate, have the illusion of, falsely remember, imagine, clubs.

Platonic number theorists believe that number is real and not material, i.e. a real idea. — Wayfarer

It's a bit confusing, because Platonists are considered realists about math. The anti-realists in the debate would be conceptualists or nominalists, so they would say that numbers and their relations are ideas in the mind, or social constructs, not independent ideas in some Platonic realm.

It's also interesting because many materialists who are also realists are highly suspicious of Platonism. And Platonists may or may not be realists about the physical world. They may even think the material world is actually mathematical. I would guess Plato was realist about matter being something. It was the various particulars, which were imperfect imitations of the forms, right?

And when I leave a room full of people then walk back in a few minutes later, it is as if the conversation went on without me. Weird. — Real Gone Cat

I think that's God's way of trolling us.

n other words, consciousness is like a song on an old cassette tape that stops when you press the STOP button, and starts up again from the exact same point when PLAY is pushed. To the song (i.e., the consciousness) no time has passed at all. — Real Gone Cat

Except that when the song status up again, it appears as if stuff was going on while the song was stopped. The time on the clock, the snow on the ground, the latest news, etc.

So the characteristic view of materialism is that humans, and everything else, are material entities, the consequence of physical laws, their actions transmitted via material mechanisms, and having material consequences. Furthermore, that is a view that many educated people believe in and defend. — Wayfarer

It's consistent with taking science at face values which explains the universe's development from the Big Bang where there were no minds to star formation to Earth to simple life developing until finally we get to a point where you have complex nervous systems similar enough to our own to call it mind.

The one way around all that is to interpret QM so that it is consciousness which collapses the possible universes into one with the history we observe. Humans or before us, animals, or aliens, or whatever mind collapsed it, it was just a giant probability wave, or something like that.

They'd just say that the real things we experience don't continue to exist after the experience ends. — Michael

But what makes a perceived tree more real than a dream tree for the idealist?

'd say for one because we experience real things. — Terrapin Station

We also experience unreal things, so the realist needs something more to justify what's considered real.

One problem with the argument is that dreams are epistemically distinguishable from waking experience, in that they do differ quite a bit from waking experience. It's just that usually our ability to judge is suspended while dreaming, although not always. In lucid dreaming, we do realize we're having a dream, and can take control of it to some extent. It's not like we go to sleep and experience another life just like the one we're having, such that we can't tell which is the real life upon waking. Dreams often don't make sense, they're jumbled up and weird. They don't follow the rules of waking perception.

However, the reality of dreaming does raise the spectre that all experience is going on inside my head. If I can dream of people, trees, colors, sounds, even feels on occasion, then what makes my perceptions fundamentally different? A challenge for direct realism is to account of the fact that sometimes, we do experience an internal world (this also applies to daydreaming).

This, I suppose, is the motivation for some, like Dennett (at least in the past, not sure about now), to deny that we actually dream. Instead we "come to seem to remember" upon wakening. Thus, dream skepticism can be avoided. But I find that entirely unbelievable.

So despite some pretending to be defenders of some long-lost ancient knowledge in the face of the onslaught of the Enlightenment, the concern with anti-realism is exactly co-extensive with it as sheer and utter reaction: it's only with the concern over absolute certainty does mysterianism and anti-realist sentiment gain any traction whatsoever, disfiguring the history of philosophy by transposing it's thoroughly modern concerns onto it and colouring it with a reactionary and regressive nostalgia that wishes for a time that never was. — StreetlightX

Weren't there idealists and skeptics about the external world in ancient Greek, Indian and Chinese philosophy?

I don't see how the realist/anti-realist debates, or the problems of perception are new. They're rooted in very old concerns about the nature of the world, how we know about said world, and so forth.

TGW is right, concerns about the external world (or what exists) present a hard problem. One that has challenged minds, both ignorant and well read, since people starting doing philosophy.

What I call an atom is also something observable in experience. — Agustino

Not until electron tunneling microscopes were invented. Atoms were purely theoretical constructs created to explain the various forms matter takes (or to be more accurate, ontological posits), and then later, various experimental results. Now that we have tools to see and manipulate atoms, they're more than just theoretical abstractions. Also, chemistry doesn't work at all without atoms.

All that being said, atoms aren't fundamental, they're made up of subatomic particles and you have all the QM probability wave weirdness going on. Also, the particles themselves are said to be point particles, meaning they have no length or width. But more importantly, atoms, photons, electors, are abstracted away from colors, tastes, etc of everyday objects. What we know of them is physics, which is heavily based on math. Which leads to the possibility that the only real properties are mathematical properties.

Consider the table. It feels solid, looks brown and polished, sounds a certain way when you thump on it. But all of that can be explained in terms of light and sound waves, empty space with tiny atoms bound together by some magnetic force. The table of physics is very different from the table we see or hear or feel.

What's the difference between the material chairs and the mathematical chairs? — Agustino

Material chairs are made up of physical stuff such as atoms and their bonds. Mathematical chairs only have mathematical properties. There is no physical stuff. Surely you've heard of Max Tegmark and his claim that the universe is mathematical. Instead of particles or fields or space being the ontological structure, it's numbers and their relations.

What does it mean chairs exist because we perceive them? Nobody ever said that. Berkeley said chairs exist because they CAN be perceived. — Agustino

Berkeley said "to be is to be perceived". Plenty of people on these forums have argued along those lines. They call themselves idealists or anti-realists, or have you been absent the various idealist/realist debates?

The idea that reality would somehow exist in itself adds nothing. It is a term invented by thinkers who seemed to have reasons to distinguish an invisible yet existing reality from its visible parts. — jkop

Maybe so, but there have always been parts of the world invisible to us. A lot more of it has been made visible to us thanks to technology, but there is still dark matter, electrons, black holes, etc.

Metaphysics doesn't deal with matters of fact. When I say idealism is true, I don't mean the same thing as when I say chairs are true. — Agustino

By chairs being true, you mean chairs exist? So when you say that idealism is true, you don't mean that chairs exist because we perceive them, you mean that it's simpler to say that chairs exist when perceived as opposed to materialy, or mathematically, or what not.

They are not things out there which can be the case or can fail to be the case. They are frameworks or lens through which you can look at the world. — Agustino

That would be an anti-realist lens to look at the other frameworks with.

You can't be curious about something by considering alternatives which would change nothing if they were true. Even asking "which is the case?" doesn't make any sense. — Agustino

I can be curious about scientific or historical findings that have no impact on my daily life, so that's simply not true. Humans can be interested in all sorts of things having nothing to do with everyday life.

Neither is plausible, and regardless of what Kant's particular take might be I see no good reason for a realist to speak of things in themselves. — jkop

How can you be a realist and not suppose there are things in themselves? What exactly are you a realist about? This is very confusing.

If I'm a metaphysical realist, I suppose the world exists independent of us, regardless of what we say, perceive or know about such a world. The world is as it is, and will continue to be long after we're gone.

If I'm a platonist, then I suppose that numbers exist as they are regardless of what sort of mathematical discoveries we fail to make. They existed before our species could count, and they will persist after the universe is without life. And so on.

And this matters because? — Agustino

It matters the same reason for asking any sort of questions about existence. How do we get here, how big is the world, did it have a beginning, and so forth. Humans have this curiosity about such questions. And some of the proposed answers bother us, and are preferably avoided.

It may not affect our daily routines, but it can affect how we think or feel about the bigger picture. Anyway, metaphysics isn't ethics, and some people don't see a use for philosophy beyond ethics. That's their prerogative.

Haven't the people who wrote stories about it imagined it? — John

Yeah, seems like imagined, visualized, pictured, and conceived are all getting jumbled together. So, I don't think any human can actually visualize a trip to a nearby star, but they can imagine a story in which a trip is made, or perform the calculations for the propulsion system based on estimated weight of ship, crew, food, etc.

This tangent got started by the claim that you don't need to be able to picture cutting down 70 trees to conceive it. One can simply perform the math of cutting down 70 trees for the average human with an axe or chainsaw. It's not a problem for the reality of cutting down that number of trees.

Being able to visualize and being able to conceive are separate abilities.

I can conceive of building a starship and traveling to a nearby star, but I can't actually imagine it. Hasn't stopped people from writing stories about it.

The whole fun is making yourself into a creative genius, or into a rich man, and so forth. — Agustino

In the optimal, tailored life of your own choosing, you can to do exactly that. In the real world, plenty of people would like to become a genius, rich or famous, but for one reason or another, can't or don't.

What do you mean by "appear" here? Obviously you can't mean it in the sense that we see something happening that isn't being seen? — Michael

I mean we experience the world as if stuff happens when nobody's around. I used the word appear to avoid realist sounding language. The subjective idealist can deny that anything actually happens. We only perceive it as if it did.

And how is that any different to the idealist's explanation that there just is a world of mental phenomena that performs steps A, B, and then C? — Michael

The objective idealist can do that. I don't see how the subjective idealist can perform those steps. It's just a brute fact of experience that a lot of stuff appears to have happened in between minds perceiving things.

Then why is there a forest and not some other thing? The realist has the same questions to answer as the idealist, just pushed further back along a proposed causal chain. — Michael

Cause of the Big Bang. There are entire fields of science to explain how the forest got there.

If so, I'm guessing you prescribe to naive realism? — Michael

No possible way TGW prescribes to naive realism. I would be beyond shocked. That would be like Landru coming on here and explaining why he voted for Trump.

But why the forest and not some other experience, to reiterate Tom's question. Realism has a really simple explanation. What's the (subjective) idealist explanation, just because?

The fact that I know why I shot you (I just sort of felt like it) should not be the determining factor in whether I should be held responsible for it. — Hanover

But why did you feel like it? Reminds me of the Radio Lab show where it mentioned one of the detectives who gave the Green River Killer a series of interviews to try and find out why he killed. They never received a satisfying answer. Probably the killer himself didn't really know why. He just felt like it (rationalized as the women deserved it). Maybe the explanation is neurological or developmental.

Nothing wrong with that, right? — Aaron R

If it's just an intellectual challenge, akin to playing chess or doing crossword puzzles, then nothing wrong. But I suspect for a lot of people interested in metaphysics, there is the nagging question of whether one's preferred metaphysics is true. That eventually leads to questioning its assumptions, and taking other metaphysical systems at least a little bit more seriously.

So, is it OK if POTUS is a liar? Trump claiming that Clinton was beneficiary of 'millions of illegal votes', with not one shred of evidence or on any grounds. Is it OK if the 'world's most powerful man' engages in twitter wars about such matters? Seems ridiculous to me. — Wayfarer

Well, he's not POTUS yet. But yeah, he needs to take a four year break from those kind of shenanigans.

I always wondered if you ate a meal on the Holodeck at a fine restaurant in 1970s Paris, upon leaving the holodeck, would the food and drink dematerialize, or would it continue to nourish you?

To be crass, what does holographic stool look like outside the Holodeck?

You can image Holographic bars where people got roaring drunk, exited the program and then immediately sobered up as all that holographic alcohol dissipated. You can return straight to duty after a grand night out on the town.