I hold no stock in the private language objection. A society of people born with unremovable visors on their heads with sensors on the outside and a screen on the inside displaying a computer-generated image of the environment could develop a language, talk about the environment, and lives their lives just as well as we can. Let's even throw in the inverted spectrum hypothesis and have different screens output different colours (but consistent for each individual), just for fun.

You are losing me here.

Sure, when we use a telephone we hear someone indirectly. Are you suggesting that undermines direct realism? — Banno

You said this, as if it were objectionable:

"Pretty ad hoc. Now we have both direct and indirect perception happening in the same individual for the same event."

It's not objectionable. It's quite ordinary. We just disagree on which things fall within the category "direct" and which things fall within the category "indirect".

Yep. But he is not only a mental image, or a firing of brain cells. He is public in a way that whatever indirect realists say they see, isn't.

It appears to me that you have moved on to equivocating about what it is that indirect realists suppose it is that is perceived. — Banno

You claimed that it's impossible to talk about things unless we can see them directly, and so I provided an example of something that we can talk about but haven't seen directly. So your objection fails.

We don't directly see Napoleon but can still talk about him. We don't directly see ships but can still talk about them.

Now we have both direct and indirect perception happening in the same individual for the same event. — Banno

Yes? That's how indirect perception works. You directly perceive some X and because of that indirectly perceive some Y. Even the direct realist must accept that this is how television and telephones work.

That's exactly right. We can talk about Napoleon because there is more to him than the firing of neutrons. He is not an hallucination. — Banno

The point is that we don't need to directly see him to talk about him, and we don't need to directly see ships to talk about them.

If the thing one sees is only ever "the visual cortex being active in the right kind of way" then we would have no basis for agreeing that there is a ship. — Banno

I didn't say only ever. I explicitly said here that "in the non-hallucinatory case there is both hearing voices-as-mental-phenomena and hearing voices-as-distal-stimulus", with the former satisfying the philosophical notion of directness — as explained here — and the latter not.

If what one really sees is always private — cortex states, sense-data, whatever — then nothing in experience can fix reference to a public object. — Banno

I object to this use of the word "really". It's a weasel word, as you said. The proper phrase in the context of this discussion is "directly see" — again, as explained here.

And we don't need to directly see something to "fix reference" to it. You and I can both talk about Napoleon.

On the view I’m defending, epistemic directness is not a matter of what is phenomenally present to the mind at all.

...

Directness, on my view, concerns what our judgments are about, not what appears in experience. — Esse Quam Videri

But direct (naive) and indirect realism, as traditionally understood, are concerned with what sorts of things are phenomenally present to the mind (and the epistemological implications). That's the nature of their disagreement.

I've addressed this elsewhere, but I think part of the problem here is that there are newer brands of "direct realism" that, in adopting the term "direct realism" to mean something else, have fabricated a dispute with indirect realists that isn't really there. Indirect realists aren't necessarily in conflict with every position that calls itself "direct realism". We need to look past superficial labels to the substance of the claims made.

An article I often refer to in these discussions is Semantic Direct Realism:

The most common form of direct realism is Phenomenological Direct Realism (PDR). PDR is the theory that direct realism consists in unmediated awareness of the external object in the form of unmediated awareness of its relevant properties. I contrast this with Semantic Direct Realism (SDR), the theory that perceptual experience puts you in direct cognitive contact with external objects but does so without the unmediated awareness of the objects’ intrinsic properties invoked by PDR. PDR is what most understand by direct realism. My argument is that, under pressure from the arguments from illusion and hallucination, defenders of intentionalist theories, and even of relational theories, in fact retreat to SDR. I also argue briefly that the sense-datum theory is compatible with SDR and so nothing is gained by adopting either of the more fashionable theories.

The problem is that you are using your definition of "I see X" (such that it is true only if X is a real object in the environment) to (mis-)interpret their claim "I see mental phenomena" (and is why your accusation that indirect realism entails an homunculus is a strawman).

The indirect realist might argue that "I see X" just describes the visual cortex being active in the right kind of way, regardless of what the eyes are doing or what distal objects exist, and so I see things when I have visual hallucinations and hear things when I have auditory hallucinations (and don't see or hear anything if I have brain damage but otherwise functional eyes and ears). This is an ordinary use of English vocabulary.

And the things I see and hear when I hallucinate have properties that can be described, such as their colour, and is how we distinguish between hallucinating one thing and hallucinating something else. Given that there is no real object in the environment when I hallucinate, the colours I see when I hallucinate are not microstructural properties of something's surface, or wavelengths of light, or anything of the sort; the colours I see when I hallucinate are mental phenomena, and it is acceptable to say that I see these colours.

I'll copy the argument from Epistemological Problems of Perception:

1. Nothing is ever directly present to the mind in perception except perceptual appearances. (Indirectness Principle) Thus:

2. Without a good reason for thinking perceptual appearances are veridical, we are not justified in our perceptual beliefs. (Metaevidential Principle)

3. We have no good reason for thinking perceptual appearances are veridical. (No-Good-Reason Claim)

4. Therefore, we are not justified in our perceptual beliefs.

The most minimal version of indirect realism is simply an acceptance of (1), where "directly present" is a substantial claim about phenomenology.

The more skeptical indirect realists may also accept (3), and so (4), although strictly speaking they can reject (3), e.g. if they agree with the naive colour realist that colours exist "out there" but disagree that these are ever directly present to the mind (the distinction I made in earlier posts between token and type identity).

And direct realists, in their attempt to argue that (4) is false, argue that (1) is false.

Indirect realism, as you are presenting it, seems to depend on the idea that knowledge of the world is justified by first securing knowledge of phenomenal character and then inferring outward. — Esse Quam Videri

Then perhaps I haven't explained myself clearly, because indirect realism argues that because perception of the world is not direct (i.e. its features do not manifest in phenomenal experience) phenomenal experience doesn't justify our knowledge of the mind-independent nature of the world, hence there being an epistemological problem of perception.

They hear hallucinated voices. — Banno

Yes, and hallucinated voices are mental phenomena. Ergo, the thing being heard is a mental phenomenon.

The Common Kind Claim is that this sense of hearing voices also occurs in the non-hallucinatory case, i.e. in the non-hallucinatory case there is both hearing voices-as-mental-phenomena and hearing voices-as-distal-stimulus.

The indirect realist claims that it is only hearing voices-as-mental-phenomena that satisfies the philosophical sense of directness (as explained here) and that it is only in virtue of this that hearing voices-as-distal-stimulus is possible — hence the latter being indirect perception.

And when you hallucinate, you don't see anything - that's kinda the point. — Banno

Arguing that schizophrenics don't hear voices, only hallucinate voices, is such a pointless argument that fails to address the actual philosophical substance of both direct and indirect realism. The phrase "the schizophrenic hears voices and sees faces in the walls" is a perfectly ordinary and acceptable phrase in the English language; it is meaningful, true, and does not entail anything like a homunculus.

This attempt to avoid the important phenomenological and epistemological issues by deferring to grammar or the dictionary, splitting hairs over the "one true" meaning of the verbs "see" and "hear", is hopelessly misguided.

You might want to use the phrase "I see X" only if there's the right kind of physical interaction between your body and some distal X, whereas others might want to use the phrase "I see X" whenever their visual cortex is active in the right kind of way, regardless of what, if any, distal causes there are. Even if it were a misuse of language to use the phrase "I see X" in this latter way, it does not follow that direct realism is true and indirect realism is false, because their dispute is far more significant (explained in my previous comment) than a dispute over which kinds of events are described by the phrase "I see X" in ordinary, everyday language.

And "I see X" ought not be conflated with "I directly see X". The philosophical term "directly" matters. Indirectly seeing distal objects is still seeing distal objects. So you appear to be guilty of equivocation in arguing that if you see the ship then you directly see the ship.

But this view assumes that (1) the wavefunction is a real thing and (2) that consciousness is what is needed to cause the wavefunction collapse. — boundless

Well, I'd at least question the use of the phrase "is needed" in (2). If the wave function is real and quantum states really are in a superposition until something collapses them then that doesn't entail the binary choice between either a) only consciousness can collapse the wave function or b) only something other than consciousness can collapse the wave function. There's also c) consciousness and other things can collapse the wave function.

Maybe consciousness isn't special, but that doesn't mean it's ineffective. It's just as real and world-affecting as any other physical phenomenon, and maybe it (sometimes) does play a (non-unique) role in collapsing the wave function (if there is such a thing).

You’re treating phenomenal character as something like an epistemic instrument - a reading from which we infer how the world is, much like a thermometer reading. — Esse Quam Videri

On the view I’m defending, phenomenal character is not a “reading” at all. It is not truth-apt, not accurate or inaccurate, and not something whose reliability is assessed independently of judgment. — Esse Quam Videri

These are not contradictory positions.

It is both the case that (a) the phenomenal character of experience is not truth-apt and the case that (b) we use the phenomenal character of experience to make inferences about the environment. (b) is exactly what John and Jane do in the example I gave; their assertions about the wavelength of light emitted by the screen are not made apropos of nothing — they derive their conclusion from the phenomenal character of their experience (coupled with their knowledge of the wavelengths of light that are usually responsible for such an experience).

My view doesn’t require that phenomenal character be explained by an object’s qualitative property manifesting itself in experience. — Esse Quam Videri

But the naive realist does make this claim, and it is this claim that indirect realists reject. The naive realist believes that the phenomenal character of experience isn't just the phenomenal character of experience but also the phenomenal character of the environment. They believe that "there are in nature colors, of a distinctive kind that we are all familiar with, i.e., that colors are simple intrinsic, non-relational, non-reducible, qualitative properties ... not micro-structural properties or reflectances" and that our colour perception is veridical if and only if the phenomenal character of our experience is the same as the phenomenal character of the environment.

And I can sympathise with this naive view. It's tempting to imagine the world as literally being coloured in the exact same way that my experience is coloured (i.e. not just in the sense of reflecting certain wavelengths of light). I think even the non-naive realist thinks something similar with respect to geometry, i.e. shape, size, distance, orientation, etc.

But at least with respect to colour (and other secondary qualities, à la Locke), the world just isn't this way. Any inference about the mind-independent nature of the world from these secondary qualities is open to scepticism. That's really all there is to indirect realism. Often this goes hand-in-hand with the semantic claim that it's appropriate to say that we see and hear and feel and taste and smell these secondary qualities — something which those like Banno seem to object to — but I don't see this as philosophically relevant (e.g. this grammar doesn't entail anything like a homunculus).

On the view I’m defending, "phenomenal character" is not what John or Jane are making inferences about — Esse Quam Videri

I agree; they are making inferences about something in their environment. But they are using the phenomenal character of their experience to make this inference, much like someone might use a thermometer to make an inference about the temperature of a pot of water. If this isn't what you mean by "epistemic intermediary" then I don't really know what you mean by the term, and I'd argue that whatever you mean isn't a requirement for indirect realism to be true.

To put it in overly simple terms, the epistemic question that gave rise to the dispute between direct and indirect realism is "can we trust that the world is as it appears?", with direct realists answering in the affirmative and indirect realists answering in the negative.

To refer back to and extend my post to Banno above, the naive colour realist justifies their affirmation of the epistemic question by arguing that:

P1. Colours as manifested in phenomenal experience are of a distinctive kind that we are all familiar with, i.e simple intrinsic, non-relational, non-reducible, qualitative properties
P2. The character of phenomenal experience is explained by an actual instance of the apple's colour manifesting itself in phenomenal experience
C1. Therefore, apples are coloured in the distinctive kind that we are all familiar with, i.e simple intrinsic, non-relational, non-reducible, qualitative properties (... not to be conflated with micro-structural properties or reflectances, or anything of the sort)

Both the direct and indirect realist believe P1. The direct realist believes P2, and so deduces C1. The indirect realist rejects P2, and so cannot deduce C1, legitimising scepticism about the mind-independent nature of the world (i.e. C1 might be false).

So direct realism is true if and only if P2 is true and indirect realism is true if and only if P2 is false. My comments regarding resemblance or representation were just to say that indirect realism can be true even if C1 is true, although if modern science is to be accepted then it's clear that C1 is false, and so P2 must be false (hence why the Wikipedia article says "indirect perceptual realism is broadly equivalent to the scientific view of perception").

In other words, this "something" needs to act as an epistemic intermediary rather than a merely causal intermediary, — Esse Quam Videri

So let's take the dress that some see to be white and gold and others black and blue. Let's simplify it for ease to a computer screen that some see to be red and some orange.

Do you accept that it is possible that all three of these statements are true:

1. John sees a red screen
2. Jane sees an orange screen
3. The screen emits only a single wavelength of light

I would say that it is possible that all three statements are true; the photo of the dress and the worldwide reaction to it suffices to prove this. So even though there is a sense in which John and Jane see the same thing (the screen) there's another sense in which they see different things (a red screen and an orange screen respectively).

In the context of (1), (2), and (3) all being true, it must be that the words "red" and "orange" are not referring to the wavelength of light emitted by the screen (which for the sake of argument I will say is 630nm, within what we would consider the "red" range). It is true that Jane sees an orange screen but it is not true that Jane sees a screen emitting a wavelength of light between 590nm and 620nm.

In the context of (1), (2), and (3) all being true, the words "red" and "orange" are referring to the phenomenal character of their experience. This phenomenal character is the "epistemic intermediary" from which they infer some mind-independent fact about the screen, with Jane (incorrectly) inferring that it is emitting a wavelength of light between 590nm and 620nm and John (correctly) inferring that it is emitting a wavelength of light between 625mn and 750nm.

Here's the problem of 'mixing' concepts of different contexts. Yes, the 'hard problem' is very relevant. But there is no compelling evidence that 'consciousness' has a special role in quantum mechanics. And even those who does give consciousness some kind of 'role' in quantum mechanics generally say that consciousness doesn't 'do' anything to physical reality. Rather, QM is a tool that is used to predict how the knowledge/beliefs of observers evolve in time. — boundless

It's not clear what you're saying.

Quantum mechanics is an attempt to describe the behaviour of all matter and energy in the universe. If consciousness exists and is a physical phenomenon then quantum mechanics can, in principle, explain the origin and behaviour of consciousness. And consciousness, like every other physical phenomenon in the universe, interacts with and affects the behaviour of its environment. So just as the physical phenomenon of electricity can "move" any surrounding matter — both at the quantum scale and the macro scale — so too can the physical phenomenon of consciousness.

It seems to me that to deny that consciousness plays a role in the behaviour of other physical phenomena is to either deny that consciousness exists or to deny that consciousness is physical (and so is some other kind of phenomena that is affected by but cannot in return affect physical phenomena).

This is a largely irrelevant semantic point but I don't think representation requires intention. If John and Jim are identical twins (or lookalikes) then I see no problem in saying that John's facial features are an accurate representation of Jim's facial features. It's not just a judgement we might make but also a (presumably) mind-independent geometric fact.

If you don't like the phrase "sensory content may or may not represent the environment" then perhaps the phrase "the sensory content's features (shape, size, distance, orientation, colour, etc.) may or may not resemble the environment's features".

The point I am making is that even if the environment has properties that resemble the properties that manifest in sensory experience, and even if English grammar describes the interaction between the body and the environment as "seeing the environment", if there is such a thing as sensory content distinct from the environment then it's still indirect realism. It is the features of this sensory content that inform our intellect and with which we make judgements about the environment, but given the distinction between this sensory content and the environment we cannot use sensory content alone to determine that it accurately resembles the environment (at best we can only determine that it is causally determined by the environment) leading to the exact epistemological problems that direct realists are trying to avoid — and in the extreme case to Kant's transcendental idealism.

We somehow need to "look past" sensory content to determine if it accurately resembles the environment. Some say that this is impossible in principle, whereas others say that modern technology has allowed us to do this, with such things as the Standard Model describing the mind-independent nature of the environment — but the picture of the world as described by the Standard Model (matter and energy as excitations of a quantum field) is very different to the world we are familiar with, proving, I think, that the original sceptical fears concerning the epistemological problem of perception were accurate.

Are you willing to claim that the character of experience is not determined, at least partly, by things in the world? Surely not. — Banno

These are two different claims:

1. The phenomenal character of experience is determined by distal objects
2. The phenomenal character of experience is determined by the direct presentation of distal objects

Direct realism, as defined in that article, asserts (2). The addition of "the direct presentation of" is important. It's the defining aspect of direct realism. (1) can be satisfied by a simple causal relationship, and is consistent with indirect realism (and even Kant's transcendental idealism, with the mind-independent nature of distal objects (noumena) being otherwise unknowable, entailing the exact kind of epistemological problems that direct (naive) realists are trying to avoid). (2) requires something more; something that indirect realists argue doesn't obtain.

The "direct presentation of" is a substantial claim about phenomenology, and requires a scientific study of the body, the brain, the environment, and phenomenal experience (whatever such a thing is, whether reducible to neurological phenomena, emergent non-physical phenomena, or something else). It cannot be deflated by a semantic analysis of English grammar.

Making sense of this "direct presentation of" is the trickier part, but I think two paraphrased assertions taken from here and here provide a starting point — as they are consistent with the direct (naive) realist's goal of avoiding epistemological problems:

a. There are in nature colours of a distinctive kind that we are all familiar with, i.e simple intrinsic, non-relational, non-reducible, qualitative properties ... not micro-structural properties or reflectances, or anything of the sort
b. The character of your experience is explained by an actual instance of the apple's colour manifesting itself in phenomenal experience.

This, to me, seems to be arguing that there is a token identity between redness as a property of my phenomenal experience and redness as a mind-independent property of the apple.

But whatever so-called "colour" properties the apple has, they are not colours in the "intrinsic, non-relational, non-reducible, qualitative" sense (they are, at best, micro-structural reflectances), and nor do they manifest in phenomenal experience (they only causally determine phenomenal experience). So naive colour realism fails on both counts.

Redness as a property of phenomenal experience (which is an "intrinsic, non-relational, non-reducible, qualitative" property) is nothing like any of the apple's mind-independent properties (e.g. its molecular structure). If you don't like the grammar of saying that we see this redness then by all means don't, although I don't know how you then make sense of a sentence such as "some see a white and gold dress and some see a black and blue dress" because it's quite clear to me that in the context of this sentence the colour terms are referring to the phenomenal character of each person's experience (which differ between individuals) and not the pixels on the screen or the wavelengths of the light (which are the same for everyone). But that's a tangent to the philosophically (and scientifically) relevant point that (a) and (b) are both false.

A direct realist ... holds that light is reflected from the ship, focused by the eye and incites certain neural pathways associated with things of that sort — Banno

As does the indirect realist.

... and that this process is what we call seeing a ship. — Banno

The dispute between the direct and indirect realist isn't just a semantic dispute about whether or not it is proper to describe the preceding chain of events using the English phrase "I see a ship" (or "I see a mental image of a ship"). It concerns the nature of sensory experience and the type of relationship it has to the ship. Both agree that there is a causal relationship, but the direct realist argues that there's a much more substantial relationship; one in which information about the mind-independent nature of the ship is given in the sensory experience, avoiding the epistemological problems that indirect realists claim are there.

The SEP article on the problem of perception, as one of the steps in defining direct realism, says that it requires that "the phenomenal character of experience is determined, at least partly, by the direct presentation of ordinary objects", and I think that this is the important part.

But we must unravel exactly what it means for something to be "directly presented" in the phenomenal character of experience, and as explained here, I think the only sensible interpretation is that there is a token identity between the phenomenal character of experience and the mind-independent properties of the ship. If there is no token identity, only a causal relationship, then it's not direct presentation. Even a type identity would be insufficient, as that simply leaves the phenomenal character of experience being an accurate representation of (i.e. resembling) the object, and this representational realism is still indirect realism; as explained further in the article, "this is why many naive realists describe the relation at the heart of their view as a non-representational relation".

The epistemological question concerns the mind-independent nature of the world. For example the chemical composition of an apple and it reflecting certain wavelengths of light has nothing to do with a point of view or a particular context. It just is what it is.

The naive colour realist then goes one step further and says that the surface of the apple is coloured in the simple, non-relational, non-reducible, qualitative sense that we are pre-scientifically familiar with, and that this has nothing to do with a point of view or a particular context, and that our experience of it is veridical if and only if this colour is the one that we see, and that anyone who sees a different colour is seeing it wrong.

So it may be that the sensory content is the same in both veridical and non-veridical cases. — Esse Quam Videri

I would argue that the fundamental dispute between the direct and indirect realist concerns the relationship between sensory content and distal objects.

Sensory content has properties, or qualities, and we describe these properties using such words as "red" and "sweet" (even if we also use such words to describe other properties, i.e. those that are causally responsible for such sensory content, like reflecting certain wavelengths of light).

Are these properties the properties of the distal object in the sense of token identity? If so then direct realism is true, else it is not. You might not want to describe the latter as "seeing a mental representation" but it would still be the case that sensory content is a mental representation, and I would say that that's all it takes for indirect realism to be true.

We then have an epistemological problem to address. If sensory content is a mental representation then can we trust that it is accurate, in the sense that the sensory content resembles the distal object. If the properties of the sensory content are the same as the properties of the distal object in the sense of type identity, i.e. in a sense that would satisfy realist colour primitivism ("colors are simple intrinsic, non-relational, non-reducible, qualitative properties ... not micro-structural properties or reflectances, or anything of the sort"), then our sensory content is accurate, else it isn't.

And I think the science is quite clear that the properties of sensory content are nothing like the properties that are causally responsible for them, and the fact that we often use the same word to refer to both has led many to equivocate.

I think the point being made is that the same wavelengths of light can cause different colour experiences in different individuals (e.g. because of different biologies).

This fact wouldn’t make sense if colour terms exclusively refer to wavelengths of light. A term like “red” can refer to 700nm light or it can refer to an object reflecting 700nm light or it can refer to the type of colour experience that 700nm light is typically responsible for in most humans.

As a particular example, consider the photo of the dress that some people see to be black and blue and others white and gold. The colour terms as used in the preceding sentence must refer to some mental/physiological phenomenon, because it’s not the case that some people see one wavelength of light and some people see a different wavelength of light, and it’s not the case that everyone sees the same colours but that a large group of people consistently forget the meaning of the words “black”, “blue”, “white”, and “gold” when asked to describe what they see. I really do see white and gold even though the wavelengths of light that are stimulating my eyes are the wavelengths that typically cause me to see black and blue.

The “object of perception” is the entire periphery and environment. That is what we see. An apple isn’t an “object of perception” because that would exclude everything else. I’m not sure why people exclude everything else in these discussions but I expect it is to help their arguments. — NOS4A2

Okay, but it's still the case that almost all of that environment isn't in direct physical contact with my eyeball; only the light is. So clearly "direct perception", if direct realism is to have any merit, isn't so simplistic as direct physical contact between our sense organs and the objects perceived.

At any rate, our eyes contact the light that bounces off an apple “directly”. — NOS4A2

Yes, but our eye isn't in direct physical contact with the apple. If your simplistic interpretation of direct perception were correct then we could only say that we directly see the light reflected by the apple, not that we directly see the apple.

Because when I look at a perceiver there is nothing between him and the rest of the world. His eyes touch the light and atmosphere “directly”, for lack of a better term. — NOS4A2

But our eyes don’t (usually) touch apples “directly”, yet direct realists claim that we see apples directly. So although there is ambiguity in what the word “direct” means in the context of “direct perception”, it clearly isn’t about our sense organs being in physical contact with the so-called object of perception. If it were that simple then direct realism (at least with respect to sight and hearing and smell) would have never been in consideration at all.

There is, so it is claimed, direct perception of distal objects even though there often is some third physical intermediary (light, air) between our sense organs and said objects.

I would tend to say that a hallucination is not the perception of an image, but the experience of imagery plus a false judgment. — Esse Quam Videri

Then isn't a veridical experience the experience of imagery plus a true judgement? I believe Clarendon is just saying that the imagery (mental phenomena) that occurs when we hallucinate is indistinguishable from the imagery that occurs when we have veridical experiences.

I am wary of reifying mental images into objects of perception — Esse Quam Videri

What does it mean for something to be the object of perception? Because hallucinations are hallucinations of something; voices, faces, monsters, etc.

This is where I think people are letting irrelevant matters of language muddy the issue. Even if you don't like the grammar of the phrase "I hallucinate mental phenomena" it is still the case that the voices I hallucinate — and their qualities like pitch and tone — are mental phenomena, not distal stimuli (else it wouldn't be an hallucination).

You've introduced "mental images" into your model in order to explain hallucination. — Esse Quam Videri

Isn’t an hallucination, by definition, a (waking) mental image that does not “correspond to” and is not caused by some appropriate distal object?

And isn’t a dream, by definition, a (sleeping) mental image that does not “correspond to” and is not caused by some appropriate distal object?

I don’t see how anyone can sensibly reject the existence of mental images. We might disagree about their nature, i.e are they reducible to neurological phenomena or are they non-physical emergent phenomena, etc., and we might disagree about their relationship and resemblance to distal objects, but they clearly do exist.

Indirect realism is still realism, so I don’t understand the relevance of those references.

We don’t really know what mental phenomena — or as scientists of perception call them, percepts — are, but they exist, whether reducible to neurological phenomena or as emergent phenomena. They are what occur when we’re awake, when we’re dreaming, when we’re hallucinating, and when having some scientist directly stimulate our brain, and they are what don’t occur when we are unconscious, regardless of how the rest of the body is reacting to stimuli. They and their qualities are neither identical to nor similar to the molecular structure of an apple’s surface or the wavelengths of light that it reflects, firmly showing that positions like naive colour realism are false. Similar reasoning holds for taste and smell and so on. That’s all it takes to support indirect realism as I see it. Locke’s distinction between primary and secondary qualities is well established.

So I think the Wikipedia article is correct when it says “indirect perceptual realism is broadly equivalent to the scientific view of perception”, regardless of whether or not philosophers have “moved past” such labels, because it’s not the label that matters but the underlying phenomenological and epistemological claims.

I’m explaining what I believe most indirect realists believe. Mental phenomena exist and have qualities that are neither identical to nor similar to the mind-independent properties that causally determine them, and so the qualities of metal phenomena provide a misleading picture of the mind-independent nature of the world.

These are the substantial phenomenological and epistemological claims that direct realists dispute, and this dispute can neither be solved nor deflated by arguing that the English phrase “sugar is sweet” means “the chemical structure of sugar activates T1R2/T1R3 GPCR on taste cells”.

It’s a dispute that can only be addressed by a scientific study of the body, the brain, and sugar, and I think the current scientific view favours indirect realism over direct realism; the evidence is quite convincing that, whatever first-person experience is, it is not constituted of the mind-independent properties of distal objects (even if it is causally determined by them).

Mental phenomena are either reducible to neurological phenomena or are emergent. They are what occur when we dream, and what don’t occur when we are unconscious (even if our taste buds are chemically reacting to apples).

These mental phenomena have qualities that, although often causally determined by particular mind-independent properties of mind-independent objects, are neither identical to these mind-independent properties nor similar to them.

Given the distinction and dissimilarity between the qualities of mental phenomena and the mind-independent properties that causally determine them, there is an epistemological problem of perception.

This is what indirect realists, both historical like Locke, and modern argue. And the naive realist, i.e. the phenomenological direct realist, disagrees, rejecting anything like the primary and secondary quality distinction. They claim that mind-independent properties are not just causally responsible for the phenomenology of experience but are actual constituents of it.

The newer semantic direct realists who try to turn the problem into one about language and the meaning of the English phrase “the apple is red” neither absolve naive realism nor refute indirect realism. They’re just addressing an unrelated and unimportant issue. The actual philosophical issue is one that applies to people without a language and/or from 100,000 years ago as well (even if they are not equipped to express the issue themselves), and to non-human animals with different sense receptors who may even see colours and taste tastes that we can’t even imagine.

Yet the deflation is set out before you. — Banno

It's not. It's a red herring that distracts from the actual phenomenological and epistemological questions. Do mental phenomena exist, and if so are its properties the mind-independent properties of things like apples (or do they in some sense resemble them)? If mental phenomena do exist and if its properties do not resemble the mind-independent properties of things like apples then indirect realists are correct and there is an epistemological problem of perception.

You have a penchant for telling naive realists what they think. — Banno

I'm explaining the historical distinction between direct and indirect realism, and how each position addresses the epistemological problem of perception. Locke's distinction between primary and secondary qualities is a fitting example of indirect realism, with his direct realist opponents rejecting this distinction.

There are legitimate phenomenological and epistemological differences between direct and indirect realism that can only be addressed by a scientific study of the world, the body, the brain, and possibly the mind, and that cannot be "deflated" by some semantic argument that "X is red" means "X causes such-and-such an experience".

This is why I phrased my post carefully, and why I posted the picture I did. The relevant dispute between direct and indirect realism concerns whether or not a) there are mental phenomena and whether or not b) the qualities of these mental phenomena are (also) mind-independent properties of things like apples. If (a) is true and (b) is false as indirect realists claim then there is an epistemological problem.

Being sweet is having a chemical structure that activates T1R2/T1R3 GPCR on taste cells. — Banno

That's not what naive taste realists (or naive colour realists with respect to colour) mean. The historical dispute between direct and indirect realism concerns phenomenology and epistemology, and these problems are neither solved nor dissolved by (re-)interpreting the phrases "is sweet" or "is red" as meaning "having the mind-independent properties to cause such-and-such physiological/mental phenomena in such-and-such organisms".

The phenomenological dispute between direct (naive) and indirect realists concerns whether or not a) there are mental phenomena and whether or not b) the qualities of these mental phenomena are (also) mind-independent properties of things like apples. Naive realists believe either that (a) is false or that (b) is true, and so that there is no epistemological problem, whereas indirect realists believe both that (a) is true and that (b) is false, and so that there is an epistemological problem. And I think that today's science of perception supports the indirect realist view (even if mental phenomena is reducible to neurological phenomena).

It is true that apples have the mind-independent properties to cause me to see particular colours and taste certain tastes, but these colours and tastes are nothing like these mind-independent properties. I can't really grasp these mind-independent properties at all (my vague "understanding" of the Standard Model notwithstanding). All I really grasp is my body's reaction to them.

so isn't all that answered in the physical description of the sequence of events? — flannel jesus

I think so, which is why the Wikipedia article on direct and indirect realism says "indirect perceptual realism is broadly equivalent to the scientific view of perception that subjects do not experience the external world as it really is."

I think the science clearly shows that colour, taste, smell, etc. are the product of our biology, causally determined by but very different to the objective nature (e.g. the chemical composition) of apples and ice creams.

So the traditional phenomenological and epistemological questions are firmly resolved in favour of indirect realism.

The current problem as I see it is that semantic direct realists have muddied the waters by trying to adapt direct realist terminology to mean something very different — something which doesn't actually contradict the phenomenology or epistemology of indirect realism.

My question is, don't we have a scientifically agreed upon sequence of events from "there's an ice cream in front of you" to "you're experiencing the visual sensation of the ice cream in front of you"? Like, the matter that makes up the ice cream is there, it reflects or emits photons, some of those photons hit your eyes, your eyes send signals to your brain, your brain interprets those signals and the context they're in to create your full visual-spacial-objectoriented experience of the ice cream and the space it exists in. — flannel jesus

Yes, and so the relevant questions are; what and where is colour and what and where is taste? The indirect realist says that colour and taste are something like emergent mental phenomena and not qualities or properties inherent in the ice cream (even if those things which are qualities and properties inherent in the ice cream, like its chemical composition, causally determine particular mental phenomena), whereas direct realists like realist colour primitivists say that colour and taste are not (just?) emergent mental phenomena but (also?) qualities and properties inherent in the ice cream, and that our colour and taste perception is veridical if and only if our experience "matches" what's out there.

This may help:

Cover one half of the picture, and then imagine the other half of the ice cream being a mirror of what you can see.

For the indirect realist the ice cream itself has no colour, because colour is not a property that exists outside of experience, and so it's represented as entirely black. The red, dark brown, and light brown colours are then produced by the brain in response to the eyes being stimulated by various wavelengths of light. As alluded to in my previous post, this might be better explained with reference to taste rather than vision; sweetness isn't a property inherent in sugar but a mental quality produced by the brain in response to the chemical reaction between sugar molecules and taste buds.

For the direct realist, the dark red, light red, and light brown colours are inherent in the ice cream, and in the veridical case the colours we experience "match" these inherent colours.

To perceive something is to be in unmediated contact with it. I take that to be a conceptual truth that all involved in this debate will agree on. — Clarendon

I disagree. You seem to be defining perception of X as direct perception of X, and so this would entail that indirect perception of X isn't perception of X, and so the very concept of indirect perception would be a contradiction.

With that in mind, a 'direct realist' is someone who holds that we are sometimes perceive the mind external world. That is, when I look at the ship I am directly aware of the ship itself. Thus, I perceive the ship.

This is as opposed to indirect realists who hold that we are only directly aware - and so only perceiving - mental states of our own, rather than the world out there. — Clarendon

I understand the distinction between direct and indirect realism to be better expressed by this picture (imagine a line down the middle and them to be two separate viewpoints):



Indirect realists accept the distinction between Locke's primary and secondary qualities, and that secondary qualities are qualities that constitute conscious experience and not material objects like apples and ice cream cones, i.e. the left-side of the above picture. Primary qualities like atomic composition and electromagnetic reflectance may causally determine secondary qualities, but it is a mistake to think of these secondary qualities as being properties of the object seen.

This view contrasts with direct realist views, e.g. realist color primitivism, which believe that Locke's so-called secondary qualities are in fact primary qualities, i.e. the right-side of the above picture.

This distinction explains why there is an epistemological problem of perception. If indirect realism is true then how much of the world we experience is a product of our bodies and brains and how much is really "out there", i.e. which qualities are primary and which qualities are secondary? What if even visual distance, shape, and orientation are secondary?

Incidentally I think it's a shame that so much of this discussion focuses on vision and colour at the expense of the other senses and other qualities. I wonder if the realist color primitivist would commit to realist taste primitivism.

Just a quibble but you're misusing the term "brute facts", at least as used by Anscombe and Searle. For Anscombe, a brute fact is a fact that cannot be explained, e.g. photons are massless particles, and for Searle brute facts are contrasted with other kinds of facts like institutional facts, e.g. it is a brute fact that the Earth exists but an institutional fact that Germany (as a nation) exists.

Even if you don't mean to be racist a discussion like this is going to bring out the racists, and I'd rather not have to deal with that fallout. I won't delete it but will close it for now and see what Jamal thinks when he's back on.

Proof of indirect realism and subjectivism and all that stuff obviously

Strange, for me the number under your name says 29.9k.