A person sitting with a friend who is hallucinating would probably think there is a difference if that person heard the friend begin to speak to people who weren't there or called attention to a tree if there was no tree. That person would, I think, believe the friend was not seeing a tree or people who weren't there, thereby noting a significant difference between the experience of seeing and the experience of hallucinating. Likewise, if that person's friend said "I had a dream about a tree" I think the person would not think his friend saw a tree while the friend was dreaming. — Ciceronianus the White

And the difference between seeing a tree and not seeing a tree is? Presumably seeing a tree is when a tree is causally responsible for the tree-experience, dreaming of a tree is when brain activity during REM sleep is causally responsible for the tree-experience, and hallucinating a tree is when psychedelic drugs are causally responsible for the tree-experience?

Presumably seeing a tree is when a tree is causally responsible for the tree-experience, dreaming of a tree is when brain activity during REM sleep is causally responsible for the tree-experience, and hallucinating a tree is when psychedelic drugs are causally responsible for the tree-experience? — Michael

What is this tree that is causally responsible for tree-experience if not some sort of tree-experience? I think this might be the place where our reasoning parts ways. I can agree with you if what you are saying is that one type of tree-experience (e.g. close-up view) is causally responsible for another type of tree-experience (e.g. looking at a tree from a distance.)

What is this tree that is causally responsible for tree-experience if not some sort of tree-experience? — Magnus Anderson

Well, if I at least accept scientific realism then a particular collection of fundamental particles. If I don't then some otherwise indescribable noumenon.

A fundamental particle would also be an object of experience. Even if fundamental particles were unobserved they would still be potential, or at the very least, imaginary objects of experience. Consider that Donald Trump is an object of experience even though I never met him in person.

One is talking about a simulation running inside your head by which you're indirectly aware of an external world. — Marchesk

That seems to be a contradiction: how can the simulation be running inside your head, if your head is inside the simulation? :s

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

Great quotes from Thompson and Bergson. But doesn't that sophisticated view about "points of view" arise from trying to respond to the way that the good old idealist vs realist argy-bargy made some basic sense?

Embodied cognition, or autopoiesis, or whatever, is a historical response to a question taken seriously. It surely cites that as its starting point. It would say it is a better view than say, cognitive representationalism.

So while I agree there is much that is incoherent at root about the classic framing of the issue, there was something essentially reasonable about asking the question of how sure can we be that what we experience is as direct as it appears ... once we realise that it does just appear.

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

I think that is an important point. What realism is after is the God's eye view. Naive realism supposes we just have that already - we look and we can see those colours and shapes which just are the objective facts of the world. There is a disinterested theory of truth relation that can support human beliefs about "how things really are". And threatening that with idealism - introducing a whole set of potential confounds into any truth claims - is deeply disturbing for many.

It just shows how soaked in analytic philosophy the Western mindset has become. The world has to be able to function as the truth-maker in the way propositional logic requires. Otherwise the whole house of cards could come down. There are real philosophical stakes motivating direct realism - real in the sense of being an existential threat at least. :)

Of course, I've already explained how pragmatism sidesteps that. It doesn't expect the mind's relation with the world to deliver truth, just functionality.

But anyway, science is then meant to be the way that realism escapes its discovered subjective limitations - the fact, as SX says, it is always a point of view. Science is meant to be the way to take the objective, all-seeing, God's eye view.

And then it is, but it isn't. You need to note how the ambition to see reality more clearly in terms of physics results in us thinking of mathematical formula and then reading numbers off various dials and instruments. Instead of "reading off" what our eyes and ears tell us "directly" - colours, sounds, etc - we add a whole bunch of mediating instrumentation that converts energies to numbers. Values that equations can understand.

So to get more real about reality, we in fact retreat even deeper from it into a realm of pure modelling. Our knowledge about the thing-in-itself becomes even less substantial, even more purely conceptual - even more idealistic in being all a bunch of ideas secured by the highly constrained perceptual act of not making a mistake when reporting the numerals visible on a dial.

There is every reason to be fascinated by the idealism vs realism issue. It is foundational to philosophy. It is the basis of epistemology. It is also fundamental to ontology at least in the context of philosophy of mind.

So I don't agree with SX's too easy dismissal, even though he is quite right that the best psychological account is the one he presents (well, once you add the semiosis that explains the autopoiesis, naturally).

I don't want to pretend that I've kept up with the direct realism debate, but I think this would be an issue only if it's assumed that what happens when we hallucinate or dream is exactly what happens when we're not hallucinating or dreaming... — Ciceronianus the White

But that misses the whole point by talking about the process rather than the results.

The epistemic concern is whether the world itself is how we perceive it. Once we know there is a process to perceiving, then the distinction between appearance and actuality arises. If there is a process, it could get it wrong. It could even invent. It could all be an invention so far as we could ever know.

So you are simply avoiding the issue in question.

Hallucinations and dreams come into it as "objective" proof that we could be trapped inside a fantasy even though normal waking experience feels so undoubtedly real. They are the counterfactuals (the counterfactuals SX wrongly says aren't available) which fatally undermine simple realism. The question then becomes - in a rigorous philosophical sense - how do you apply the brakes before slithering all the way to the other extreme of idealism?

So some real work needs to be done here. It can't be glibly dismissed.

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. 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.

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. But it must be conceded that there is a strong intuitive link. Without God there is no ready explanation for shared experience and it is human nature to grasp at any explanation rather than none, even if the explanation generates at least as great explanatory gaps down the track - which the 'realist' explanation does because it cannot explain how consciousness occurs.

Perhaps the passionate 'realists' are those that viscerally accept that intuitive link between 'non-realism' and solipsism, and the 'non-realists' (including both idealists ('anti-realists') and those that think the distinction is just words) do not.

It's interesting that, in The Matrix, although the protagonists' experiences while in the Matrix are not 'real', they are shared. They work together and communicate with one another while in the Matrix to achieve a goal.

There's room to reflect whether the idea of being in a simulation would be sad if it were a non-solipsistic, shared experience like in The Matrix. For me, it appears sad at first but then when I reflect on the sharedness of the experience with other conscious beings, I feel that it is not.

An older version of the simulation idea is the Vedanta notion that the world is a dream of Brahman. I find that notion attractive. Maybe the difference is that the Matrix is operated by hostile entities, whereas Brahman's dream is not.

My saying I like the Brahman idea might seem that I'm contradicting my earlier statements that the 'realist' and 'non-realist' position statements are not logically distinct. As defence, I'll offer that I don't think the Brahman idea is a well-formed logical proposition. Rather, it is a way of mentally framing one's attitude to life. It belongs in a context of mysticism, not of analytic philosophy, so it doesn't have to bother with things like definitions and syllogisms.

There is no logical link of 'non-realism' to solipsism. If there were one, it would have been published by now, — andrewk

Didn't Descartes write that book? Anyway, to the degree that doubt is possible, belief in turn becomes uncertain.

The logic is the usual reciprocal one of dialectical argument. So you are right that this is a pseudo-problem of a sort. Most folk don't move swiftly on to the synthesis - the realisation that if belief is fundamentally limited, then ... reciprocally ... so in fact must be the doubt.

They call it dependent co-arising out East. Each extreme arises only in presence of its "other". So any limitation on one is going to be mirrored in some formally true sense that further thought ought to be able to uncover.

That is the path which leads to Peircean pragmatism and scientific reasoning. We start the whole game going by just being willing to hazard a best guess. So we claim a belief in axiomatic or hypothetical fashion. Then do our damnedest to doubt it and see if the belief survives. Our degree of belief because reciprocal to the weight of inductive evidence. Our doubt and uncertainty can be quantified in those terms.

So there is definitely a logical argument to be had at the core of this important epistemic debate.

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

It shouldn't have anything to do with people's emotions - their desires or wishes.

I can see that you might suspect people of picking the philosophical side that seems to best confirm their pre-philosophical understandings of themselves. Of course folk want to be standing on the side of the right answer.

But that isn't why idealism~realism is of foundational importance to philosophy itself. Once it is accepted that somehow reality is an appearance, a point of view, for us, then a can of worms has been opened.

We can be just as sure from the outset that the doubting can't actually slither all the way down the slope to solipsism. As you say with the Matrix, even the solipsists attempts to imagine what that would be like lack convincing detail.

It sounds fine in a general way, until Berkeley has to start muttering about us all being minds within the mind of God. Solipsism is self-contradictory when you really get into its own necessary ontic commitments.

So we know solipsism can't be a final destination we could arrive at just on those kinds of logical (not emotional) difficulties. The alternative is not a well-worked out one.

But that still leaves the big issue of how we resolve the epistemic tension between doubt and belief. And what could be more mission-critical for philosophy? We actually need a robust method, a robust "theory of truth".

And if that has to boil down to induction more than deduction, dialectics rather than predicate logic, then I guess that is when we will discover how emotional the logicians can be. :)

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.

So little at stake for what?

For the eudaimonia of sentient beings.

Who cares about a Higgs Boson or whether P = NP?

It seems reasonably likely that discoveries about Higgs Bosons may lead to technological advances that help sentient beings to attain eudaimonia. So there is likely something useful at stake there. I am not so sure about P vs NP, since plenty of P problems are still intractable in feasibly available computing time.

In any case, so far as I know, people don't have long, passionate, circular debates over either of those. They may work towards potential solutions of the problem, but that's technical work, not trading opinions.

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?

I didn't mean to imply that it was all a waste of time. I'm just saying there have been philosophers who eschewed a certain kind of a philosophy for a long time. I have earnestly wrestled with metaphyical issues, and I still do. But pragmatism, etc., has IMV helped me keep my eye on the ball. Some issues now look like dead ends, which opens up time for other more 'living' issues.

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. — Marchesk

For me this word "real" is part of the "problem"? 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.

I have no sincere doubt about being-with-others or being-in-the-world. The universe of the scientific image (a non-primary abstraction that functions as a tool within the "real real world" of being-with-others) includes my brain, etc., so I have reason to think that my experience of this physical substratum is mediated. But apparently we all mediate this substratum in roughly the same way, so that the world can be shared. I think others see red, blue, yellow as I do. They feel love and hate, understand calculus, and so on, more or less in the same way. Even if this was "in" the Matrix (and it sorta is in terms of mediation), it would still be 'real' in the most emotionally relevant sense, at least for me.

Scott Aaronson has a wonderful essay detailing why the P = NP problem has all sorts of ramifications for philosophy, well worth reading, incidentally:

https://www.scottaaronson.com/blog/?p=735

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

Remember that maxim about the typical accuracy of sentences starting with 'So you....'?

Even if this was "in" the Matrix (and it sorta is in terms of mediation), it would still be 'real' in the most emotionally relevant sense, at least for me. — t0m

I see your point better I think. There is an assumption behind idealism~realism which is about being an immaterial soul locked in a material body, a physical world. So selfhood is taken for granted. It is all about starting with the bare givenness of experience. Then we have to work out what is really real.

And a corrective to that is instead not making self primary. The real first ground of being is the communal one. We are already in a world - the social tribal one. Our first experiences as babies is human contact. It is everything. So the communal mind - in some very important sense - is there before the private self becomes individuated (and aware of being trapped in a body that is trapped in a world).

So this seems to go against Heidegger. Maybe you will correct me on that.

But it is definitely pragmatism - Peirce's ultimate theory of truth being based on "that judgement towards which a community of thinkers would eventually tend".

And it is completely in line with my social constructionist viewpoint of human psychology. We are not born selves, but become individuated beings via the shaping constraints of our family, our tribe, our culture, our era.

I would point out how it is theistic notion of supernatural spirit or soul - the Romantic notion of human psychology - which is at odds with this view. So while you talk about it in an appealing warm and cosy ways, the emotional value, that fits quite happily with a naturalistic perspective.

I have no problem at all in first experience being about the raw feelings of human contact, being drawn into the human web of relations. So first there is you. Then later I discover I.

Babies of course are also busily discovering their own hands belong to them, and that the world exists in its various recalcitrant dimensions. But the emotion of social interaction could be primary in a way that the idealism~realism debate manages to by-pass.

You could ask the question of how would that change the game?

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.

There is an assumption behind idealism~realism which is about being an immaterial soul locked in a material body, a physical world. So selfhood is taken for granted. It is all about starting with the bare givenness of experience. Then we have to work out what is really real.

And a corrective to that is instead not making self primary. The real first ground of being is the communal one. We are already in a world - the social tribal one. Our first experiences as babies is human contact. It is everything. So the communal mind - in some very important sense - is there before the private self becomes individuated (and aware of being trapped in a body that is trapped in a world).

So this seems to go against Heidegger. Maybe you will correct me on that. — apokrisis

You did get my point, yes. But this is "with" Heidegger. "Dasein" in its everydayness is lived by the "they" or the anyone. Dasein is "primordially" "being-in-the-world" or "being-with-others." And the goofy word 'Dasein' is used instead of 'human' or 'subject' in order to dodge the Cartesian tradition which has concealed the phenomenon of "primordial worldliness" or "being-in" with its now invisibly- ready-to-hand pre-interpretation.

So we tend to start with a massively loaded notion of ourselves and our situation. That "first wrong move" constrains everything that follows. Hence a destructuring of metaphysics is necessary in phenomenology, a breaking of the concealing crust of "pre-interpretedness." He also very memorably writes: "only as phenomenology is ontology possible."

But it is definitely pragmatism - Peirce's ultimate theory of truth being based on "that judgement towards which a community of thinkers would eventually tend". — apokrisis

Yes, the "everyday self" is especially reminiscent of pragmatism. Dasein is fundamentally care. Even time itself can be explained in terms of the shape of this care, a shape described by Heidegger with temporal metaphors but seemingly untimelike apart from its explanatory power with respect to the time of being-with-others and physics-time. Basically time is "de-worlded" as we move from the individual working on some individual project, then to the social world's holidays (for instance) and finally to the pure clock-time of physics. This is brilliantly presented in The Concept of Time, also known as the "first draft" of B&T.

Then of course know-how is lit-up by the analytic of Dasein as the everyday mode of disclosing entities. They are perceived in terms of their use, in terms of their in-order-to for-the-sake-of. Equipment exists as a network. A pen makes sense in terms of paper to write on. We write a paper in-order-to get published in-order-to get tenure for-the-sake-of living a life of the mind. But this "in-order-to" and "for-the-sake-of" is by no means any more explicit than the tool that vanishes the more it is available or ready-to-hand. The theoretical mode of "just staring" has been given an unjustified priority (concealing the phenomenon of know-how) in order to "ground" eternal "truths" understood as correctness as opposed to the disclosure that makes correctness possible.

Finally, Heidegger includes (in his own terms) the dialectic between the they-self and the 'authentic' self. "Authentic" seems to be a misleading translation of eigentlich. It should perhaps be "real" Dasein or Dasein at its most Dasein, which is to say a "poetic" discloser of being. I think "authentic" Dasein is just Dasein in the mode of revolutionary-'abnormal' of discourse. "Inauthentic" Dasein is the routinized normal discourse of "idle talk" that doesn't dig deeply into what is said. This is pretty much what Rorty made of eigentlich. I think it also describes a mode of experiencing time. It is not a sense of monotonous hurriedness but involves a reticent, anxious joy.

And it is completely in line with my social constructionist viewpoint of human psychology. We are not born selves, but become individuated beings via the shaping constraints of our family, our tribe, our culture, our era. — apokrisis

Yes. I agree complete. Perhaps I stress more than you do, however, the developed individual as the "cutting edge" of the group. On the other hand, I'm sure we both see a dialectic.

I would point out how it is theistic notion of supernatural spirit or soul - the Romantic notion of human psychology - which is at odds with this view. So while you talk about it in an appealing warm and cosy ways, the emotional value, that fits quite happily with a naturalistic perspective. — apokrisis

Hmm. I think you are projecting a little on my position. But I will grant that the "hero-image" of the individual can be traced back to the religious tradition. If anyone is aware of this as hero-image, I think it's me. I'm concerned with a phenomenological objectivity, an accurate description of how hero-images generally constrain interpretations of the world. So physical science isn't as important to me, except as it figures as a notion of the "truly" real within particular "understandings of being" for-the-sake-of enacting a particular version of the "knowledge hero." I don't think of my view as warm and fuzzy. It almost presupposes a certain "death" of more typical basic frameworks, those same frameworks it demystifies and tries to explain in terms of a generalized will-to-virtue. (This will-to-virtue is the postulated brute fact, though one could presumably trace it back in terms of biology, etc. But it would explain this same tracing-back that explains it.)

What realism is after is the God's eye view. Naive realism supposes we just have that already - we look and we can see those colours and shapes which just are the objective facts of the world. — apokrisis

The God's eye view would be the all-encompassing view i.e. the view that allows us to see everything there is in the universe. That's quite different from saying that colors and shapes are the objective facts of the world. I do not have much of a problem with the claim that objects of our experience, such as colors and shapes, are reality itself. In other words, I have no problem with this kind of direct realism. I merely think it's unnecessary to think in such a way. What's problematic is the kind of direct realism that is applied to knowledge that is derived indirectly i.e. via reasoning. It's one thing to think that our objects of experience, such as colors and shapes, are reality itself and another to think that our assumptions or inferences, such as that the way we see colors and shapes is the way other people see them, are reality itself.

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.

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. — Marchesk

I think that most people would agree with that. I am not a realist, I am a phenomenalist. And I agree with what you're saying. I agree that there is a larger world humans are but a small part of. I agree that we are late on the evolutionary scene. I agree that we only occupy the land surfaces of this planet. I agree that there are tons of other stars and planets out there. That's not where the disagreement between realists and phenomenalists, or at the very least me, resides. The disagreement lies in the MEANING of these statements. And one characteristic feature of all realists is that they REFUSE to explain in sufficient detail what they mean with their statements. Which is exactly what you're doing. You did not explain what the word "real" means. You did not explain what phenomena this category that we identify with the word "real" includes and what phenomena it excludes. What you did is you merely explained one mystery with another.

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.

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.

You 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.

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.

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.

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.

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?

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. — Marchesk

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.

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.

As I said before, I think the issue of the immediate object of perception is a non-issue. You can say that you're immediately aware of the occurrence of pain or you can say that the occurrence of pain is the immediate awareness of some external stimulus. What, exactly, is the difference between these two accounts? What would it take for one to be true and the other to be false?