What, exactly, is the difference between these two accounts? What would it take for one to be true and the other to be false? — Michael

Here's a thought. If a neurological account of qualia could ever be provided, then perhaps a sophisticated form of direct realism would be defensible, because then a clear relationship between optics and brain processing could be shown. Perhaps.

What, exactly, is the difference between these two accounts? — Michael

One account makes the external stimuli open to skepticism. To the extent we care about skepticism, it matters. We don't have to care, but some people are worried about justifying knowledge.

What would it take for one to be true and the other to be false? — Michael

Pain is a bad example, since pain isn't an external property. So what would it take for color realism to be the case? The external environment has to be colored in the way we see it when it's not being perceived by humans.

I doubt that can be successfully defended. It sounds incredible. Other attempts at color realism sound dubious on semantic grounds. I'm not sure what sort of property is being defended.

Shape is bit different because a mathematical description for it can be given. This is different than color, where the experience of color bears no relationship with the wavelength of light, other than that's what we end up experiencing.

And what reasoning does the realist have to support his claim that we perceive an independent world (of other people and inanimate objects)? Presumably they believe it to be the most parsimonious explanation for the occurrence and regularity of experience? So as I said, the reasoning is the same. — Michael

Keep in mind that we start off with naive realism, then realize there are problems for the naive view. This leads to alternative suggestions. But if a form of naive realism can successfully be defended, then there is no need to worry about the alternatives, and the problems they raise.

Again, I agree that there is a physical world that exists in space and time regardless of whether or not human beings are around to perceive it. My question is: what does that mean? I gave you my answer in one of my previous posts. You never gave yours. — Magnus Anderson

You answer is that it exists as a potential to be perceived. My answer is that it just exists. Question for you: how does a potential causally explain our evolution?

ou can avoid solipsism by arguing that the most parsimonious explanation for the occurrence and regularity of experience is the existence of an independent world of stimuli that are causally covariant with these experiences. It's the exact reasoning that the realist uses. — Michael

True, but that's the exact reasoning the indirect realist uses. The direct realists doesn't need to infer an independent world. We already perceive it.

The difference is in whether one believes that the immediate object of perception is these experiences or the external stimuli, and in whether or not the properties of the experiences are (also) properties of these external stimuli. — Michael

Agreed. That's the issue at stake in the debate.

For example, one might say that the pain and the feeling of heat when putting one's hand in a fire are the immediate objects of perception – that then allows one to correctly infer the existence of a fire – and that the pain and the feeling of heat are not properties of the fire but are properties of the experience – the phenomena that emerges from the brain activity stimulated by sensory receptors in one's skin. — Michael

Right, but this will apply to everything we perceive, and other people are perceived.

That's the big kicker and why solipsism is so hard to defeat.

Never mind the rest of my post, eh? Where has philosophy definitely relegated physicalism to the nonsense bin? I'm not aware of it. — Benkei

It hasn't.

nd one characteristic feature of all realists is that they REFUSE to explain in sufficient detail what they mean with their statements. — Magnus Anderson

There is a physical world that exists in space and time regardless of whether humans beings are around to perceive it. And by physical, I mean the world as best approximated by physics. Maybe natural is the better term, since physics is an incomplete, ongoing human endeavor.

This natural world is the causal explanation for how we got here, and what we are.

There is no logical link of 'non-realism' to solipsism. If there were one, it would have been published by now, and no non-solipsist 'non-realist' that understood logic would dare to deny the link. — andrewk

The link is perception. If the philosophical position results in being unable to say that one is perceiving things or events external to oneself, then solipsism follows on empirical grounds. Or at least skepticism concerning other people, since we know about other people by perceiving them.

Sure, the link can be denied on ontological grounds. Idealism will just state that other minds exist, and sometimes those other minds have the same or similar ideas in mind at the same time as you do, and thus there is a kind of shared, intersubjective experience.

But it's by ontological fiat that solipsism is avoided. It's not epistemologically grounded. Even Kantian idealism has this problem, since my knowledge of other people is constructed by my categories of thought when perceiving others. Ontologically speaking, other people are part of the noumena, as far as I can know, because my knowledge of them is dependent on perception. Even though Kantians will say all humans perceive as I do, I can only know about them via perception, and thus they could just be another category of my perceptual/cognitive process.

Thank heavens for supervenience physicalism, eh? One less thing to clean off your windscreen. — Wayfarer

Epiphenomenal ectoplasm is where I draw the line on meaningful philosophical discussion, but that's just me.

I kind of like the sound of it, though.

What do we mean by "real"? Or do we mean all sorts of things in all sorts of contexts? I think a primary meaning involves "being-with-others." That's the real real world, I tempted to say. What matters is how shared a situation is. If we're all in the Matrix together, then the Matrix is as real as we might want it. — t0m

I think it primarily means there is a larger world humans are but a small part of. We are late on the evolutionary scene, we only occupy the land surfaces of this planet, for the most part, and there are tons of other stars and planets out there.

The real world is the far bigger and older world, where only a little tiny bit of it has human society.

It seems reasonably likely that discoveries about Higgs Bosons may lead to technological advances that help sentient beings to attain eudaimonia — andrewk

So you think an issue worth debating needs to have technological application for it to help attain eudaimonia?

Do you feel the same way about art, literature or music?

It is remarkable how much sound and fury this issue generates (eleven pages showing now on my computer) when there is so little at stake. — andrewk

So little at stake for what? It has large stakes in metaphysics. It's been of importance to many philosophers. Anyone can ask whether what they perceive is real or not, and plenty of people do at some point, even if it's over a joint.

I watch the tv show Mr. Robot, and it continuously raises the question of to what extent our perceptions are accurate. Do we perceive the real world, or is it an illusion? And then tons of viewers on Reddit debate whether the show is a simulation, employs time travel, parallel universes, replicants, or whatever theory is used to explain events on the show.

You seem to think the issue doesn't matter. Okay. I'm sure there are plenty of people who think that mathematical or physics problems don't matter either. Who cares about a Higgs Boson or whether P = NP?

My attempt to explain this is that people who find it important do so because they believe that non-acceptance of the 'realist' (ie materialist) account logically entails solipsism, which in turn seems to signify ultimate loneliness, and that one's closest and most important relationships are a delusion. — andrewk

What difference does it make what the motivation is for someone finding a philosophical puzzle interesting or important? The point is that some people find it worth discussing. I could wonder why you don't find it important, but it's totally irrelevant to the inquiry itself.

If an idealist says, "Everything out there is made of the same stuff as in here." and the materialist says, "Everything in here is made of the same stuff as out there.", then they are both saying the same thing. "Physical" and "mental" is a product of dualism and is what creates a problem where there isn't one. — Harry Hindu

This doesn't work, because we have experiences of things which aren't out there, and the things out there can't fully explain the things in here.

Phenomenalists such as Ernst Mach call this "potential experience". That's what is meant when people say that things exist or have certain properties when we're not looking at them. It does not mean anything more than that. Unfortunately, many people, I am pretty sure you among them, are not willing to accept this description. Why is this so? — Magnus Anderson

Because I find it extremely lacking, and it makes science into a fiction. It also means other people are a potential experience.

What does it mean for the sky to be blue when you're not looking at it? — Magnus Anderson

It means under certain lighting conditions (it's sunny out), the air molecules scatter light at a wavelength that we see as blue.

But we're not taking about 'properties' in the abstract. We're talking about perceptual properties, which, by definition, are related to a perceiver. Again, you're confusing the one with the other. — StreetlightX

Are some of the perceived properties also properties of the object being perceived? Locke thought so.

Well if you can make sense of what a thing looks like when there is no looking involved, then be my guest. — StreetlightX

On the direct realist account, perceived objects would have the same properties when nobody is perceiving them. I can't fully buy into this, because it's clear to me some properties are dependant on the perceiver. But some are clearly not.

And what would 'objective' here mean? After all, there is an objectivity to looking itself, which is what studies of illusion show us. — StreetlightX

Objective would mean the properties that give rise to the experience. This would be the properties of the external inputs.

Correct. — StreetlightX

That's a cheap way to dismiss a philosophical issue. But whatever.

Then you have a poor grasp of the English language. — StreetlightX

I didn't come up with the direct/indirect realism debate, so what you're really saying is that professional philosophers who think it's meaningful don't have a good grasp of the English language.

And what does this have to do with perception? Jesus. — StreetlightX

How the fuck do you think scientists came up with a theory of QM? By sitting in their armchairs and dreaming it up? Or running a shit ton of experiments and trying to make sense of them?

But that's not a sensical claim. It is not even wrong. It's a grammatically correct word salad. — StreetlightX

But it's not. I have no problems understanding it.

Make up your mind: does science 'extract properties which aren't creature dependant' or is science 'creature dependent'. You can't have you cake and eat it. — StreetlightX

Science attempts to be creature independent, and describe the world as it is. That's why we arrive at theories like QM.

then by definition it clearly isn't' talking about anything to do with perception. — StreetlightX

If it has nothing to do with perception, how would we know about it? On an empirical account of knowledge, there must be something perceptible which leads us to inferring the non-perceptible properties of things.

Presumably the same thing that makes a direct realist so sure that there has to be something responsible for the experience (so sure that the things we see continue to exist even when not seen). — Michael

That the alternative is an absurd, gappy and brute account of individual experiences, or solipsism?

Or appeals to God and universal consciousness.

But not: what does it look like when there is no looking involved? — StreetlightX

But doesn't science do exactly that by extracting the properties which aren't creature dependant to arrive at an abstract picture? Nagel's view from nowhere. That's the point of objectivity. To get around our idiosyncratic human experiences.

I think you missed my edit: "or just 'noumena' if you don't even want to be a realist about the Standard Model". — Michael

Yeah, if you want to go full Kant. Streetlight's post would also be Kantian. The external inputs could be the noumena.

It's just that when you arrive at noumena as your reality, why even bother being realist? What makes that more likely than the alternatives? What makes a Kantian so sure there has to be something responsible for experience?

Incidentally, is there a Godwin's equivalent law for metaphysical discussion and QM?

And evolution is an abstract way of describing the very real interaction of fundamental wave-particles. — Michael

If one is realist about wave-particles, but not biological structures, sure.

I think one can be a realist about the fundamentals (e.g quantum mechanics and the Standard Model) but an anti-realist about macroscopic objects. Allows one to avoid reductionism. — Michael

One can. Wouldn't that be mereological nihilism? And does biology still fit in there somehow?

Yeah, it does follow.

Evolution is a fictional account of species because it didn't happen on an anti-realist reading, anymore than God created all the animal kinds in six days. It's just more palatable to modern empiricism.

But so what? Are you suggesting that anti-realism is wrong because it doesn't allow for realism? — Michael

I'm suggesting anti-realism is wrong because it can't explain why anything happens. The instrumentalist explanations are just-so stories. We don't know why appearances have the structure they do. We invent atoms and electromagnetism to make sense of it all. Evolution didn't happen, it's just a story we tell ourselves about our origins, because we replaced the religious account.

Landru was real good at this game.

whereas the anti-realist argues that the object of perception (and the thing we talk about) is the coffee. — Michael

But that anti-realist can't answer the question of why there is coffee, while the realist can appeal to chemistry. For the anti-realist, coffee is brute, and chemistry is a just-so story. Something that makes sense of appearances.

Sure, but what would it otherwise be? — StreetlightX

The external object or environment itself. Direct realism is a sophisticated form of naive realism. Things are as they appear, under normal conditions where the perceiver is functioning properly.

What you call 'anti-realism' only makes sense when countervailed by 'realism', but what you call 'realism' can be given no sensical content as far as I can see, which makes 'anti-realism' itself a position which states nothing, that marks a difference which makes no difference. — StreetlightX

Collapsing the distinction between realism and anti-realism is a form of anti-realism. And you can do that, but what about those "external inputs"? Are they just appearances too?

What about the entire physiological account of perception? Is that an appearance? Is there any reason to suppose anything else exists other than my own appearances? You're providing a sophisticated form of solipsism.

What would it mean for something to be 'unlike' what it appears? Would it appear differently? — StreetlightX

Yeah, the bent stick in water appears straight outside of water. The solid table is mostly empty space on the microphysical level. The earth rotates around the sun, despite appearances. There are massive galaxies of billions of stars, despite it looking like there are only a few thousand points of light in the night sky. Most the EM spectrum is invisible to us. There is a giant list of appearance/reality distinctions.

It's not clear that this is a sensical statement either. — StreetlightX

How is it not? What are the external inputs? What are their properties? Do any of those properties show up in our experiences?

It only supports 'indirect realism' if the very distinction between direct and indirect realism makes sense. But of course, the point is that it doesn't. — StreetlightX

I don't see how it doesn't. You've basically quoted evidence that our perception is internally generated from a combination of external inputs, and ongoing processing in the brain (conversation between cortex and thalamus).

Wakefulness is nothing other than a dreamlike state constrained by external sensory inputs... the brain sustains the same core state of consciousness during REM sleep and wakefulness, but the sensory and motor systems we use to perceive and act can’t affect this consciousness in regular ways when we’re REM-sleep dreaming. Consciousness itself doesn’t arise from sensory inputs; it’s generated within the brain by an ongoing dialogue between the cortex and the thalamus. — StreetlightX

This part is particularly intriguing. I can just hear some philosophers gnashing their teeth over this. Would love to see Dennett's reaction to it.

Things don't look or feel like anything when not being seen or felt. It's naïve (realism) to suggest otherwise. — Michael

So we're left with mathematical abstractions?

Very interesting, thanks. That would seem to largely support indirect realism, even if you're not interested in framing it that way. It also seems to support the Cyrenaic view of perception, which was that it was the result of bodily movements, with the addition of external inputs.

It doesn't really help alleviate skeptical concerns, or tell us much about the nature of the external inputs. As Michael points out, the external inputs can be totally unlike what consciousness presents us.

When two men look at a wheel and agree that its shape is circular what that means is that their "shape" experience is similar. — Magnus Anderson

What it means is that there is a circular object that gives rise to the experience of seeing a circular shape, and that's why two people can have similar experiences. Also that's why there are two people.

The set (or more accurately, category) always refers to some range of experience. There is thus no dichotomy between experience and reality that is separate from our experience. — Magnus Anderson

Science claims otherwise. There is big universe that exists beyond and before, and after us. But our everyday experiences tell us the same thing. The big oak tree has 120 rings. It was alive before I was born, etc. And all of us were born, before we experienced anything. This goes all the way back before humans, and eventually, before life and any sort of experience.