The claim “I hear voices” in the case of hallucination is not true, though. — NOS4A2

According to what you mean by “hear”, but what you mean isn’t always what others mean, and certainly isn’t what they mean when they say that the schizophrenic hears voices.

it just boggles my mind why they’d appropriate the language used to describe those things and interactions to describe mind-dependant things and interactions — NOS4A2

Words often mean more than one thing. It boggles my mind that you don’t understand this.

I’m fine with them saying it. But I’m not fine with the indirect realist saying it, especially if accuracy is any concern.

What would be your motivation for wishing to retain the language used to describe the interactions of distal objects and the sense organs to describe mental objects and the mental organs? — NOS4A2

Because that's how the language is ordinarily used. I see colours, I feel pain, the schizophrenic hears voices.

Why must the indirect realist restrict the meaning to some specific subset of its ordinary uses?

Not that this really matters. What matters is what they mean by the words they use, not what you think is the "proper" use of the words.

And this is where my earlier comment to Banno above is relevant. Naive realists claim that we have direct knowledge of distal objects because distal objects are constituents of experience. Indirect realists claim that we do not have direct knowledge of distal objects because distal objects are not constituents of experience; they only play a causal role in producing mental percepts of which we have direct knowledge.

This is the philosophical dispute, not some irrelevant argument about the grammar of "I see X".

A voice, though, is the sound released from the larynx. To hear a voice is to have that sound affect the ears. Since neither of these things and events are present in a hallucination, to say “I hear voices” is to mischaracterize the experience.

One can distinguish between between two different hallucinations by simply describing how they are different. One might be audible or visual, for example. — NOS4A2

Saying that the schizophrenic hears voices is a perfectly ordinary and appropriate use of the English language.

If you don't want to phrase it that way then you're welcome not to, but to misinterpret someone who does phrase it that way as suggesting the involvement of the sense organs in the schizophrenic's ears is your problem, not theirs. And this kind of misinterpretation is the root of your disagreement with indirect realism.

“Hallucinate” would be a better verb than “see” when comes to such events. “I am hallucinating voices”, for instance, doesn’t imply that the sound of a voice is hitting the ear, and recognizes that some bodily activity is producing the phenomena. — NOS4A2

There is a difference between visual and auditory hallucinations and using words like "see" and "hear" to describe that difference is perfectly appropriate.

The difference concerns which of the visual and auditory cortexes are involved. The words don't imply anything about sense organs, and assuming that they do is why you are misunderstanding indirect realism.

You have to interpret another's claims according to what they mean by the words, not what you mean by them, else you're arguing against a strawman.

Indirect realism has you sitting inside your head, seeing and touching what is constructed by your nerves. — Banno

This shows the crux of the misunderstanding.

"Feel" does not mean "touch". I feel pain, I don't touch pain (rather, I touch the fire).

Unfortunately, when it comes to words like "see" and "hear" and "smell" and "taste" we don't have terms that can be separated out in this way, and so Banno conflates the meaning of "see" in "I see colours when I hallucinate" and the meaning of "see" in "I see a cow". Indirect realists are using the former meaning when they say that we see mental images, and Banno's homunculus is a strawman.

When you have an hallucination of a cow, you do not see a cow, because there is no cow to see. — Banno

I still see something when I dream and hallucinate, and that thing I see is a mental phenomenon. When I feel pain I feel something, and that thing I feel is a mental phenomenon. So there's clearly nothing wrong with the phrase "I experience mental phenomena".

This sense of seeing and feeling and experiencing is also satisfied in veridical experience – even if there's some other sense of seeing and feeling and experiencing that allows us to truthfully say "I see a cow" – and so there's clearly nothing wrong with the indirect realist saying "I experience mental phenomena" about veridical experience.

What indirect realists dispute is that seeing a cow counts as direct perception, because by "direct perception" they mean something very specific. The phrase "direct perception" is related to the epistemological problem of perception.

To make sense of this, I'll refer to What’s so naïve about naïve realism?:

The second formulation is the constitutive claim, which says that it introspectively seems to one that the perceived mind-independent objects (and their features) are constituents of the experiential state. Nudds, for instance, argues that ‘visual experiences seem to have the NR [Naïve Realist] property’ (2009, p. 335), which he defines as ‘the property of having some mind-independent object or feature as a constituent’ (2009, p. 334), and, more explicitly, that ‘our experience […] seems to have mind-independent objects and features as constituents’ (2013, p. 271). Martin claims that ‘when one introspects one’s veridical perception one recognises that this is a situation in which some mind-independent object is present and is a constituent of the experiential episode’ (2004, p. 65).

...

... Intentionalism typically characterizes the connection between perception (taken as a representative state) and the perceived mind-independent objects as a merely causal one. But if the connection is merely causal, then it seems natural to take the suitable mind-independent objects to be distinct from the experience itself and, therefore, not literally constituents of it.

The epistemological problem of perception concerns whether or not experience provides us with direct knowledge of distal objects. Naive realists claimed that experience does provide us with direct knowledge of distal objects because distal objects are constituents of experience. Indirect realists claimed that experience does not provide us with direct knowledge of distal objects because distal objects are not constituents of experience; they are simply the cause of the mental representations of which we have direct knowledge.

"Direct perception" meant that distal objects are constituents of experience and "indirect perception" meant that distal objects are not constituents of experience.

You're welcome to redefine "direct perception" if you like, but in doing so you're no longer addressing the indirect realist's claim. Your arguments against indirect realism are against a strawman.

I feel pain and see and hear things when I dream and hallucinate. You're reading something into the sentence "I experience mental representations" that just isn't there.

The trouble here is how indirect realism can produce reliable information about the number of handles on the cup. — Banno

If we agree on the physics and physiology and only disagree on the grammar then why would the indirect realist have any more trouble than the direct realist?

Your very question here seems to accept that the dispute between direct and indirect realists is about more than grammar.

If both direct and indirect realists accept the existence of mental representations as caused by distal objects then what do you think the (non-grammatical) substance of the dispute between the two is?

I don't claim not to have reliable knowledge of distal objects. I claim that mental representations are distinct from distal objects, that I have direct knowledge of mental representations, and that I have indirect knowledge of distal objects.

If it is not a performative contradiction for a direct realist to be scientific realist (i.e. believing in the existence of objects that he cannot directly see) then it is not a performative contradiction for an indirect realist to be a scientific realist.

Even direct realists can trust a Geiger counter. You're being a hypocrite.

Balls. If that were so there would not be a philosophical issue. There is no difference in the physics or physiology between direct and indirect descriptions. The difference is that the direct realist sees a cow, the indirect realist sees... something mental. You keep setting out a scientific account as if it settles the issue, but there is no disagreement here. — Banno

If you don't understand what naive realists are claiming then that's on you. They are saying much more than just "I see a cow" is true.

I think it is exactly the problem. We do not disagree on anything to do with the physiology or physics hereabouts. Where we disagree is as to the language of perception.

I say we see the cow. You say we see only the mental cow.

I don't see our approaches as meshing. — Banno

This is precisely the point I have been making since the start. The philosophical dispute between direct (naive) and indirect (non-naive) realists concerns the physics and physiology of perception. Indirect realists are right and direct realists are wrong.

Then so-called "non-naive" direct realists enter the fray, read something into the sentence "I experience mental representations" that just isn't there, and so start an irrelevant and nonsense argument about grammar.

If there is a equivocation here, it is being forced on us. But in any case, it seems we now agree that colours are not just mental phenomena. — Banno

When I say "I see colours and colours are mental phenomena" I am referring to the mental phenomena, not whatever else the term "colour" might be used to refer to.

So to repeat:

I see colours and feel pain. Colours and pain are mental phenomena. I see things when I dream and hear things when I hallucinate.

You're reading something into the grammar of "I experience mental representations" that just isn't there.

There's also the colour red. Folk knew about it well before they knew about wavelengths and three channel colour vision. — Banno

What is the substance of this? If we're not talking about wavelengths and we're not talking about mental percepts then what do we mean by "is red"? All we seem to be agreeing on is that most English speakers use the predicate "is red" to describe the apple.

That linguistic issue has nothing to do with the epistemological problem of perception. You can't see the forest for the giant red herring you've fished out.

To help you out, lets's consider us all to be deaf, illiterate mutes. We still see colours, and the colours we see have nothing to do with language.

All assertion and no argument. I'll wait until you present an argument to address—responding to mere assertions being a waste of time. — Janus

The argument was in that comment:

Experience exists within the brain. Distal objects exist outside the body. Therefore distal objects (and their properties) do not exist within experience.

The first premise is supported by neuroscience. The second premise is true by definition. The conclusion follows.

If colours are no more than mental phenomena, how is it that we agree that clear skys are blue? How is it that we agree that an ache is not a sting?

They are also linguistic, and physical. — Banno

I'll repeat myself from an earlier comment:

This is equivocation. There is "colour" as an object's surface disposition to reflect a certain wavelength of light and there is "colour" as the mental phenomenon that differs between those with 3 channel colour vision and those with 12 channel colour vision (and that occurs when we dream and hallucinate).

Despite sharing the same label these are distinct things – albeit causally covariant given causal determinism.

Those with 3 channel colour vision and those with 12 channel colour vision will agree that some object reflects light with a wavelength of 700nm, but they will see it to have a different colour appearance.

You mean like direct realism = the apple is distal object is numerically identical to the apple percept? — fdrake

I'll copy from What’s so naïve about naïve realism?:

The second formulation is the constitutive claim, which says that it introspectively seems to one that the perceived mind-independent objects (and their features) are constituents of the experiential state. Nudds, for instance, argues that ‘visual experiences seem to have the NR [Naïve Realist] property’ (2009, p. 335), which he defines as ‘the property of having some mind-independent object or feature as a constituent’ (2009, p. 334), and, more explicitly, that ‘our experience […] seems to have mind-independent objects and features as constituents’ (2013, p. 271). Martin claims that ‘when one introspects one’s veridical perception one recognises that this is a situation in which some mind-independent object is present and is a constituent of the experiential episode’ (2004, p. 65).

...

... Intentionalism typically characterizes the connection between perception (taken as a representative state) and the perceived mind-independent objects as a merely causal one. But if the connection is merely causal, then it seems natural to take the suitable mind-independent objects to be distinct from the experience itself and, therefore, not literally constituents of it.

There's a distinction between a distal object being a constituent of experience and being a cause of experience. Indirect realists accept that distal objects are a cause of experience but deny that they are a constituent of experience.

Here's the point, again; one does not see the representation; seeing is constructing the representation. — Banno

I see colours and feel pain. Colours and pain are mental phenomena. I see things when I dream and hear things when I hallucinate.

You're reading something into the grammar of "I experience mental representations" that just isn't there.

Ordinary Objects Caveat: perceptual experiences are directly of ordinary mind-independent objects in the sense that mind-independent objects reliably cause percept properties to hold which intersubjectively count as each other.

Presentation: perceptual experiences are direct perceptual presentations of their objects in the sense that perceptual experiences are perceptions/percepts and that causes of percept properties are tightly constrained by distal object properties. Like reflectance spectra tightly constraining seen colour. — fdrake

But the indirect realist agrees that mental phenomena like smells and tastes and colours are causally determined by distal objects and their properties.

So clearly direct realism cannot be defined in this way.

As I see it indirect realism is nothing more than the rejection of naive realism, with naive realism claiming that distal objects are literal constituents of experience, entailing such things as the naive theory of colour.

According to indirect realists, these are all mental phenomena, no matter what you see or feel. What you see or feel can only be a representation, so it must all be mental phenomena. — Luke

No, according to indirect realists those statements are more specifically understood as:

I directly see colours and colours are a mental phenomenon.
I indirectly see trees and trees are not a mental phenomenon.
I directly feel pain and pain is a mental phenomenon.
I indirectly feel my hand burning and my hand burning is not a mental phenomenon.

Indirect realists claim that it is only mental phenomena that is directly experienced and that distal objects are indirectly experienced, with the distinction between "direct" and "indirect" being explained in my comment here.

Unless indirect realists are allowed to have both perceptions of a mental phenomena and perceptions not of a mental phenomena?

Yes. There are direct perceptions of mental phenomena and indirect perceptions of distal objects.

Where is the evidence for how neural activity interacts with the colors your experience? — Harry Hindu

Neural representations of perceptual color experience in the human ventral visual pathway

There is no color in light. Color is in the perceiver, not the physical stimulus. This distinction is critical for understanding neural representations, which must transition from a representation of a physical retinal image to a mental construct for what we see. Here, we dissociated the physical stimulus from the color seen by using an approach that causes changes in color without altering the light stimulus. We found a transition from a neural representation for retinal light stimulation, in early stages of the visual pathway (V1 and V2), to a representation corresponding to the color experienced at higher levels (V4 and VO1).

---

I can't argue with you about something you have been vague and evasive about. If I don't know what you mean by your use of certain words, then I can't make any coherent argument about anything you've said. — Harry Hindu

See Perception # Process and terminology:

The process of perception begins with an object in the real world, known as the distal stimulus or distal object. By means of light, sound, or another physical process, the object stimulates the body's sensory organs. These sensory organs transform the input energy into neural activity—a process called transduction. This raw pattern of neural activity is called the proximal stimulus. These neural signals are then transmitted to the brain and processed. The resulting mental re-creation of the distal stimulus is the percept.

To explain the process of perception, an example could be an ordinary shoe. The shoe itself is the distal stimulus. When light from the shoe enters a person's eye and stimulates the retina, that stimulation is the proximal stimulus. The image of the shoe reconstructed by the brain of the person is the percept. Another example could be a ringing telephone. The ringing of the phone is the distal stimulus. The sound stimulating a person's auditory receptors is the proximal stimulus. The brain's interpretation of this as the "ringing of a telephone" is the percept.

The different kinds of sensation (such as warmth, sound, and taste) are called sensory modalities or stimulus modalities.

I see trees, trees are a mental phenomenon... Wait, I thought you were a realist? — Luke

As I have repeatedly said, "I experience X" doesn't just mean one thing.

I see colours and colours are a mental phenomenon.
I see trees and trees are not a mental phenomenon.
I feel pain and pain is a mental phenomenon.
I feel my hand burning and my hand burning is not a mental phenomenon.

Both the direct and the indirect realist's grammar are correct. The phrases "I see" and "I feel" have more than one meaning.

The relevant question concerns which of these are correct:

I directly see trees
I indirectly see trees

Given this, one cannot simply define "I directly see a tree" as "I see a tree". Something else is required to make sense of the words "directly" and "indirectly", and that is what I have done in this comment.

That doesn't seem to be your position, though, nor that of indirect realists. Indirect realists do not claim that the visual experience is a mental phenomenon or representation of the world outside the body. Instead, they claim that we perceive this mental phenomenon or representation of the world outside the body. — Luke

I feel pain, pain is a mental phenomenon, therefore I feel a mental phenomenon.
I see colours, colours are a mental phenomenon, therefore I see a mental phenomenon.

You're getting so caught up in the grammar of "I experience X". It doesn't just mean one thing. It is perfectly appropriate to say that we see things when we dream and hear things when we hallucinate, and that the things we see and hear when we dream and hallucinate are percepts rather than distal objects. The indirect realist recognises that we see and hear these percepts when awake and not hallucinating too, and that these percepts can be thought of as mental representations of distal objects.

I'm not sure what you take a direct perception to be. Must a distal object become part of one's body in order to have a direct perception? Who thinks this is a perception? — Luke

It seems to me as if my visual experience literally extends beyond my body and that distal objects are literally present within my visual experience. This is the naive view that naive realists accepted as true, but which the science of perception has now shown to be false. Indirect realists rejected this naive view and claimed that the visual experience is a mental phenomenon that exists within the brain and is, at best, a representation of the world outside the body.

Then so-called "non-naive" direct realists accept this indirect realist view but for some reason call themselves direct realists, probably because that get confused by the grammar of "I see X".

They've just redefined the meaning of "direct perception".

In what sense is the mind-independent nature of distal objects and their properties not presented to us via perception? — Luke

To be presented is to be present. If some distal object is presented in experience then that distal object is present in experience. If that distal object is present in experience then it exists within experience.

But experience exists within the brain and distal objects exist outside the body. Therefore distal objects do not exist within experience and so are not presented in experience. The relationship between experience and distal objects is nothing more than causal.

You seem to indicate that unless perceptions provide us with complete and incorrigible knowledge about objects, then they don't provide us with any knowledge about objects. — Luke

They don't provide us with direct knowledge. Experience is the effect, distal objects are a cause. Knowledge of effects is not direct knowledge of causes. Knowledge of causes gained from knowledge of effects is inferential, i.e. indirect.

I'm finding it hard to see how the posts you're making are related, which probably means we have very different presuppositions and ways of thinking about the topic.

So if I'm hearing you right, you believe that knowledge is only of percepts, and thus access to the world is indirect? — fdrake

I only used the word "access" because it's the term Moliere used. He said "in terms of the epistemological problem of perception we have direct access to some kind of object". Given that he referenced the epistemological problem of perception I assumed by "access" he was referring to knowledge.

Right, so for you "access" is something like introspective awareness? — fdrake

The epistemological problem of perception concerns epistemology, i.e. knowledge.

I might know that I see the colour red and taste a sweet taste but not know that some object reflects light with a wavelength of 700nm and that the cake contains sugar (e.g. because I'm a young child who doesn't know anything about physics or chemistry).

I have knowledge of percepts but I don't have knowledge of the proximal stimulus or distal object.

Describe what you see that access as, please? — fdrake

Having a rational awareness/understanding of it. I can describe the colours I see as being red or green or blue or the taste I taste as being sweet or sour or bitter.

From this I then infer the existence of some object reflecting light of certain wavelengths or some foodstuff containing certain ingredients like sugar, given that I have some understanding of the usual relationship between stimulus and percept.

Mmm... You don't have "access" to a percept. A percept is identical with either the whole, or a part of, the conceptual-perceptual state of an organism at a given time. That's a numerical/definitional identity, rather than an equivalence. Like the percept is not what perception or experience is of, the percept is an instance of perception. The taste percept of my coffee is the same as how I taste it.

The distinction there is between saying that a percept is an instance of perception vs saying that a percept is what perception acts upon. — fdrake

I have access to colours and pain and smells and tastes. These are all percepts.

When I see things when I dream and hear things when I hallucinate I am seeing and hearing something.

We have access to percepts. And we have access to the world. It is through this access that we are able to determine when we are hallucinating or dreaming and when we are not.

So, direct realism. Both percepts and world are accessible. — Moliere

Our access to the wider-world is indirect with those percepts being the intermediary. If those percepts are missing (e.g. where someone has cortical blindness) then some access to the wider-world is lost.

All you're saying is that with a CCTV camera I have access to the inside of the bank vault. But it's indirect access.

I think much of the dispute between direct and indirect realists may revolve around the fact that direct realists limit the meaning of the word "perception" to sensory perceptions that are stimulated by distal objects, whereas indirect realists give the word "perception" a wider meaning that includes non-sensory "perceptions" that lack any external stimulus, such as hallucinations, dreams and imagininings. Neither side has the monopoly on correct usage, but given the question of whether or not I directly perceive some distal object, the former meaning would typically be assumed. — Luke

Which is precisely why I have argued that the dispute over the grammar of "I experience X" is a red herring.

The philosophical dispute between direct and indirect realists concerns the epistemological problem of perception. Are distal objects and their properties constituents of experience such that their mind-independent nature is presented to us or is experience nothing more than a mental phenomenon, with is features being at best only causally-covariant representations of those mind-independent properties? Direct (naive) realists argued the former and indirect (non-naive) realists argued the latter.

The same as it means to perceive causes and effects -- one has to start somewhere. We can call that starting point "blotches of color", "cause-and-effect", "the cup", or any other such things. In terms of the epistemological problem of perception we have direct access to some kind of object, be it causes, cups, or color-blotches. — Moliere

We have access to percepts. Percepts are often the consequence of the body responding to some proximal stimulus (dreams and hallucinations being the notable exceptions). The proximal stimulus often originates from some distal object.

The nature of our percepts is determined by the structure and behaviour of our sense organs and brain such that different distal objects can cause the same percept and that the same distal object can cause different percepts (e.g. the dress that some see as white and gold and others as black and blue).

This is indirect realism. Any direct realist who claims that this is direct realism has simply redefined the meaning of "direct" into meaninglessness.

I directly perceive the entity. — Moliere

Which means what?

I'd also say there's no "distal object" -- that this is a conceit of indirect realism. — Moliere

It's a term used in the science of perception. See here:

The process of perception begins with an object in the real world, known as the distal stimulus or distal object. By means of light, sound, or another physical process, the object stimulates the body's sensory organs. These sensory organs transform the input energy into neural activity—a process called transduction. This raw pattern of neural activity is called the proximal stimulus. These neural signals are then transmitted to the brain and processed. The resulting mental re-creation of the distal stimulus is the percept.

To explain the process of perception, an example could be an ordinary shoe. The shoe itself is the distal stimulus. When light from the shoe enters a person's eye and stimulates the retina, that stimulation is the proximal stimulus. The image of the shoe reconstructed by the brain of the person is the percept. Another example could be a ringing telephone. The ringing of the phone is the distal stimulus. The sound stimulating a person's auditory receptors is the proximal stimulus. The brain's interpretation of this as the "ringing of a telephone" is the percept.

The different kinds of sensation (such as warmth, sound, and taste) are called sensory modalities or stimulus modalities.

Practicality probably. Is that the source of the indirect realist's confidence? — frank

Perhaps, yes. Both direct and indirect realists are realists rather than subjective idealists because they believe that the existence and regularity and predictability of experience is best explained by the existence of a distal world which behaves according to regular and predictable laws.

Right. The question is: what is the source of the indirect realist's confidence that the mental phenomena are caused by the dot? — frank

What is the source of the direct realist's confidence that the dot is caused by some unobservable entity?

We see colours. Colours are mental phenomena, perhaps reducible to activity in the primary visual cortex, often caused by light interacting with the eyes (although not always given the cases of dreams and hallucinations). That's indirect realism.

Direct realism claims that colours are mind-independent properties of distal objects à la the naive realist theory of colour.

These are quite clearly different positions and at least one of them is wrong. I say that the scientific evidence supports the former and contradicts the latter, e.g. from here:

A stimulus produces an effect on the different sensory receptors, which is being transmitted to the sensory cortex, inducing sensation (De Ridder et al., 2011). Further processing of this sensory stimulation by other brain networks such as the default mode, salience network and frontoparietal control network generates an internal representation of the outer and inner world called a percept (De Ridder et al., 2011). Perception can thus be defined as the act of interpreting and organizing a sensory stimulus to produce a meaningful experience of the world and of oneself (De Ridder et al., 2011).

Arguing over the grammar of "I experience X" leads to confusion and misses the substance of the dispute entirely. See here.

But the direct realist relies on the observations that support belief in electrons (like the light dots on a CRT). The indirect realist has to say that those light dots are creations of the brain, and so may not reflect the facts. — frank

Both the direct and indirect realist infers the existence of some entity from some effect it is claimed to have caused. They just disagree on which effect is directly perceived. The direct realist claims to directly perceive the dot on the screen as caused by the unobservable entity. The indirect realist claims to directly perceive the mental phenomenon as caused by the dot on the screen as caused by the unobservable entity.

If a color is directly perceived and the wavelength is indirectly perceived, and your mind with all of it's colors and sounds and feelings, are part of reality, then isn't it safe to say that you directly experience part of the world? If so, then doesn't the distinction between indirect vs direct realism become irrelevant? — Harry Hindu

The question is whether or not I directly perceive some distal object. That I directly perceive some aspect of the world (i.e. my mental phenomena) isn't that I directly perceive the particular aspect of the world that direct realists claim we directly perceive (i.e. the distal object).

Have scientists been able to explain how a physical, colorless brain causes visual experiences, like visual depth and colors? How are colors come from something colorless?

What role does the observer effect in QM play here? — Harry Hindu

The hard problem of consciousness hasn't been resolved. Some believe that it is reducible to brain activity (e.g. pain just is the firing of c fibres), and some believe that it is some mental phenomenon that supervenes on such brain activity.

Either way, few (if any) believe that conscious experience extends beyond the body such that distal objects and their properties are literally present in conscious experience. At the very least there's no scientific evidence to suggest that it does. As referenced earlier, I suspect something like objective idealism would be required for that.

What part of you directly interacts with the world? What is "you" or "I" in this sense? If you define "you" and "I" as your body, then isn't your body directly interacting with objects by holding them and with light by opening your eyes? — Harry Hindu

Different parts of me directly interact with different parts of the world. My eyes directly interact with light, the neurons in my brain directly interact with each other, etc.

Indirect realism only makes sense if you define "you" and "I" as homunculus in your head.

"I feel pain" doesn't entail a homunculus. "I see shapes and colours when I hallucinate" doesn't entail a homunculus. Saying that these very same mental percepts occur when awake and not hallucinating doesn't entail a homunculus. You're just reading far too much into the grammar of "I experience X".

The question is about why you have confidence that your observations reflect the facts, when you've concluded that your observations are creations of your brain. — frank

If the direct realist can believe in the existence of unobservable entities like electrons and the Big Bang and in the veracity of a Geiger counter then the indirect realist can believe in the existence of unobservable entities like electrons and the Big Bang and in the veracity of a Geiger counter.

Direct perception of something is not required to be justified in believing in that thing.

It's that the scientist starts by assuming direct realism, then disproves direct realism. It's an ouroboros. — frank

I don't quite get what you're saying. Flat earthers assume that the Earth is flat, do experiments, and determine that the Earth is not flat. It's not a paradox; it's just that the experiments have proven them wrong.

Direct realists assume that colours are mind-independent properties of objects, do experiments, and determine that objects are bundles of atoms that reflect various wavelengths of light. They then study the brain and determine that we see colours in response to stimulating various areas of the primary visual cortex. They've determined that that colours are not mind-independent properties of objects but mental/neurological phenomena.

What exactly do you mean by "phenomenological character"? At the moment all you seem to be saying is that waking experiences are to dreams what a photorealistic portrait is to cubism. Either way it's all mental percepts and so by any reasonable definition indirect realism.

You don't actually see a distal object when you dream and the schizophrenic does not actually hear a distal object when hallucinating. That what makes them dreams and hallucinations instead of instances of seeing or hearing real objects.

An indirect realist would argue that imaginary friends are directly perceived but real friends are only indirectly perceived. — Luke

Correct.

The first sentence is a paradox, isn't it? — frank

I wouldn't say so. That scientific realism entails indirect realism is contingent on a posteriori facts, not a priori truths. Perhaps in some alternate universe the world works differently and direct realism is true (e.g. objective idealism may entail direct realism as it could allow for an extended consciousness within which "distal" objects are literally present).

But as it stands the science of perception supports indirect realism and so a direct realist must reject the science of perception, although I don't know how he can justify that rejection.