Quite so. But then one has to explain what a hallucination of a dagger is, if not a mental image. That's not easy, because most people are absolutely sure that, like Macbeth, they see a dagger that is not there. — Ludwig V

If I paint a landscape from memory of a park I visited long ago, do I need to appeal to mental images to explain how I did it? Is it not explanation enough just to say, “I am trained to paint landscapes, I visited that park, and have a good memory, go visit the park and you can see how accurate the painting is.” I don't need to say, “I am good at painting the mental copy of the park I have in my mind.” There need not be any mental copy at all.

If I paint a landscape from memory of a park I visited long ago, do I need to appeal to mental images to explain how I did it? Is it not explanation enough just to say, “I am trained to paint landscapes, I visited that park, and have a good memory, go visit the park and you can see how accurate the painting is.” I don't need to say, “I am good at painting the mental copy of the park I have in my mind.” There need not be any mental copy at all. — Richard B

Exactly. If you are painting from a mental image, how could you distinguish between mistakes you have made because you are not very good at painting mental images - though you might still be stellar at painting actual landscapes - and mistakes you made because you are not very good at painting actual landscapes even if your mental images are a bit naff.

Does it mean when you see a cup on the table, the cup exists on the table, and it also exists in your mind? — Corvus

From my position of Indirect Realism:

Suppose in my mind I have the concept of something that I know as “cup”.

Suppose I perceive in my senses a single instantiation of this concept.

From perceiving something in my senses, I infer that there is something in the mind-external world that has caused my perception.

I can never know what this something in the mind-external world is, but for convenience I can name this unknown something after the concept in my mind, in this case “cup”.

I name the unknown cause in the world after the known effect in my mind.

I name the unknown something in the world “cup” after the concept of “cup” I have in my mind.

Similarly, if I perceive the colour of red in my mind, I can name the unknown cause in the world “red”, regardless of what actually exists in the world.

Dreams and hallucinations can be coloured (or "have colour" if you prefer), and people with synaesthesia can see colours when listening to music. This is because seeing colours (or even coloured things) is what happens when the visual cortex is active in the right kind of way, regardless of what the eyes are doing or what objects exist at a distance. This is also why cortical blindness is a thing, where the eyes react to stimuli as normal but the person doesn't see anything.

None of this entails a homunculus. That's a tired and lazy strawman.

Dreaming and hallucinating is not “seeing”. There are no eyes or receptors of that type in the brain. That’s just the figurative language of someone who cannot even see his own ears, let alone the imperceptible, mental actions occurring inside his own body.

The homunculus critique still stands unless people stop claiming that they can see the events occurring behind their eyes or somewhere in their brain. If you can see the events occurring in the brain, you have to explain how you can do so with no senses receptors in there. The problem is, though, if people cannot see the events occurring behind the eyes, they cannot see what the indirect realist is claiming they are can.

That’s just the figurative language — NOS4A2

There's nothing figurative about the phrase "the schizophrenic hears voices". The problem here is that you seem to think that the verb "to hear" refers only to the ears reacting to vibrations in the air, but it doesn't. This is most evident in those with cortical deafness who don't hear anything despite having perfectly functional ears. To hear something is for the auditory cortex to behave in a certain way, regardless of what, if anything, is happening in the ears. In ordinary situations the auditory cortex is only sufficiently active in response to signals from the ears, but it's a mistake to conflate the two.

Is it your position, then, that sensing doesn’t involve sense receptors?

Is it your position, then, that sensing doesn’t involve sense receptors? — NOS4A2

No, my position is that to see something is for the visual cortex to be active and that to hear something is for the auditory cortex to be active. Most of the time this involves sense receptors being the "source" of the signal that triggers the activation of these cortices, but this isn't necessary. This explains how schizophrenics hear voices, why those with cortical deafness don't hear anything, and the existence of synesthesia.

Then how do those cortexes see?

Then how do those cortexes see? — NOS4A2

The activation of these cortices is seeing, just as the activation of other areas of the brain is thinking and is feeling pain.

The activation of these cortexes is seeing, just as the activation of other areas of the brain is thinking and is feeling pain.

Now that we know seeing doesn’t involve eyes, where do the objects of perceptions appear, and how are you looking at them?

Now that we know seeing doesn’t involve eyes — NOS4A2

It doesn't necessarily involve eyes, but most of the time it does.

how are you looking at them? — NOS4A2

Seeing something doesn't require looking at something, just as hearing something doesn't require pointing one's ears at something. We see something if the visual cortex is active in the right kind of way, and we hear something if the auditory cortex is active in the right kind of way, and we think about something if the relevant areas of the brain are active in the right kind of way.

where do the objects of perceptions appear — NOS4A2

This is like asking where the objects I dream about or hallucinate appear. It's a nonsensical question. There is just the occurrence of mental phenomena, with qualities described by such words as "pain", "pleasure", "red", "round", "sweet", "sour", etc.

I think your slow-light apple case is a very good stress test, and it helps clarify what “direct” can and can’t mean.

If we build “direct perception” to require strict simultaneity — the object must exist at the very time of the perceptual experience — then your conclusion follows. With light at 1 m/s, after the apple disintegrates I would still have an experience as of an intact apple, and it would indeed be odd to say I am directly seeing something that does not exist now. But that shows that the simultaneity requirement is doing the work; it is not forced by the ordinary contrast between direct and indirect perception.

On the view I’m defending, “direct” does not mean instantaneous or unmediated by delay. It means that perception does not proceed by inference from an inner surrogate. In your case, what is present to perception is not a mental intermediary, but a worldly manifestation of the apple itself — its visible presence at my location. The light that carries this presence is not a numerically distinct object perceived instead of the apple; it is the means by which the apple is perceptually available across space and time.

So am I directly seeing the apple? The right answer, I think, is: I am seeing the apple, but not the apple-as-it-exists-now. I am perceptually related to the apple as it was at the relevant emission time, via its causal presence reaching me now. That is not “seeing a non-existent object” in the sense that would imply illusion or imagination. The error, if there is one, lies in the judgment “the apple exists now”, not in the perceptual relation itself.

This also answers the non-arbitrary cutoff worry. There is no threshold speed or distance at which perception suddenly flips from direct to indirect, because directness is not a function of causal delay. Delay determines which temporal aspect of the object is perceptually available; it does not introduce an epistemic intermediary. The relevant contrast is between perception as non-inferential openness to the world and cognition that proceeds by inference from a representation.

Finally, when I distinguish proximal stimulation from the intentional object of perception, this is not a retreat to indirect realism. The proximal stimulation is not something we perceive instead of the object; it is how the object makes itself perceptually available within the physical world’s causal structure. That distinction allows us to acknowledge causal mediation without collapsing perception into awareness of inner or outer surrogates.

Quite so. But then one has to explain what a hallucination of a dagger is, if not a mental image. That's not easy, because most people are absolutely sure that, like Macbeth, they see a dagger that is not there. Hence, a dagger-like object. Illusions like the bent stick are easy - we can demonstrate that the stick in water should look as if is bent - it's an actual physical phenomenon. At the moment, I'm inclined to just say that Macbeth is behaving as if he can see a dagger, and believes he is seeing a dagger - but there is no dagger and hence no perception of a dagger. — Ludwig V

That’s more or less the approach I take as well. On my view, hallucination involves mental imagery together with a false judgment that something mind-external is being perceived. There is imagery and belief-like commitment, but no perceptual relation to an object.

It means that perception does not proceed by inference from an inner surrogate. — Esse Quam Videri

The error, if there is one, lies in the judgment “the apple exists now”, not in the perceptual relation itself. — Esse Quam Videri

It's not clear to me what you mean by perception, which is probably why I don't understand what you mean by direct perception. The first quote seems to suggest it has something to do with inference but then the second quote seems to suggest that it's distinct from judgement. Could you clarify?

If it helps, consider the visor example before but assume that the person wearing the visor doesn't know that he's wearing a visor and that he believes that he has direct perception of distant objects. You've accepted before that this is indirect perception, but also said that this is because we must also judge the "accuracy" of the visor. In this case the wearer doesn't judge the "accuracy" of the visor because he doesn't even know about it. So given this, what is the difference between the visor being an intermediary and the visor being "the means by which the apple is perceptually available across space and time"? As I said once before to Banno, as he made a similar claim, the latter phrase seems like it can act as a truism that includes even a Cartesian theatre.

The proximal stimulation is not something we perceive instead of the object; it is how the object makes itself perceptually available within the physical world’s causal structure. That distinction allows us to acknowledge causal mediation without collapsing perception into awareness of inner or outer surrogates. — Esse Quam Videri

What if the light first passes through a window? What if the light has been reflected off a mirror? Like above, assume in both cases that we don't know about the window or the mirror. When, exactly, does causal mediation stop "maintaining" direct perception?

It doesn't necessarily involve eyes, but most of the time it does.

Seeing something doesn't require looking at something, just as hearing something doesn't require pointing one's ears at something. We see something if the visual cortex is active in the right kind of way, and we hear something if the auditory cortex is active in the right kind of way, and we think about something if the relevant areas of the brain are active in the right kind of way.

This is like asking where the objects I dream or hallucinate appear. It's a nonsensical question. There is just the occurrence of mental phenomena, with qualities described by such words as "pain", "pleasure", "red", "round", "sweet", "sour", etc.

Seeing something is when the visual cortex is active in the right kind of way. One needn’t have any eyes for this. So when you see something without eyes, where in time and space is this something you see, and how are you seeing it?

So when you see something without eyes, where in time and space is this something you see — NOS4A2

Where in time and space is this something you dream about? Where in time and space is this something you hallucinate? Where in time and space are the colours the synesthete sees when listening to music?

In the head.

how are you seeing it? — NOS4A2

How are you dreaming about something? How are you hallucinating something? How are you thinking about something?

Because the appropriate areas of the brain, e.g the visual cortex, are active.

I do not take the objects of perception to be momentary temporal stages. On my view, mind-external objects are temporally extended continuants that persist through change. — Esse Quam Videri

This relates back to the Ship Of Theseus. Is an object the same object after having all of its original components replaced with others over time?

It also relates back to the Sorites Paradox. If one particle of sand is removed one at a time, when is a heap of sand not a heap?

Is the problem of Indirect and Direct Realism a problem of ontology, linguistics or logic?

Both the Indirect and Direct Realist accept the temporal causal chain from mind-external object to perception in the mind of that object.

If the Sun exists at one moment in time, then the Direct Realist cannot directly perceive the Sun as they propose. However, if the Sun exists through time, is it still possible for the Direct Realist to directly perceive the Sun?

Some believe in a Block Universe, where all moments, past, present and future are equally real and some believe in Presentism, where only the present is real and the past and future don’t exist in the same way as the present does.

Argument one against Direct Realism

If Presentism is true, only the present exists, meaning that the Sun can only exist at one moment in time. Direct Realism is not valid as it is not possible to directly perceive something in the past that no longer exists.

If the Block Universe is true, the Sun exists over 10 billion years.

However, as the Theseus Paradox and Sorites Paradox shows, this is a linguistic and conceptual rather than ontological problem.

Suppose in a mind-external world at one moment in time there exists a Sun in the ontological sense. Suppose at a later moment in time this Sun loses one atom. What determines in a mind-external world that a Sun which has lost one atom remains a Sun or is no longer a Sun? There is absolutely nothing in a mind-external world that can determine when a Sun becomes a non-Sun.

Only in the human mind using language and concepts can a Sun be distinguished from a non-Sun.

If the Direct Realist is claiming that the Sun they directly perceive ontologically exists in the mind-external world, this is logically impossible, because there is no means within a mind-external world to distinguish between a Sun and a non-Sun.

However, if the Direct Realist is claiming that the Sun they directly perceive exists within language and concepts, then they are in agreement with the Indirect Realist.

If temporal mediation and non-simultaneity were sufficient to make perception indirect, then all perception would be indirect — Esse Quam Videri

Why? I directly perceive what is in my mind in my present, even if I infer that the cause was in the past.

Objects certainly exist in the mind in language and concepts, but what is the ontological nature of an object in a mind-external world? Specifically, in a mind-external world, what determines when an object becomes a non-object? What determines when a seed becomes a tree? What determines when a hill becomes a mountain? What determines when a slight rain becomes a thunderstorm? What determines when a pebble becomes a rock?

Where in time and space is this something you dream about? Where in time and space is this something you hallucinate? Where in time and space are the colours the synesthete sees when listening to music?

In the head.

The suggestion that you're watching your own mental activity is the Cartesian theater in a nutshell, my friend. How can you be a realist if mental activity is what you're watching?

How are you dreaming about something? How are you hallucinating something? How are you thinking about something?

Because the appropriate areas of the brain, e.g the visual cortex, are active.

A "how" question requests a description of an action or state, in this case how you are viewing the activity of a cortex. It wasn't a "why" question. For instance, I see something by moving my eyes in its direction, whereupon the light from that object goes into my eyes, and so on. This can be done in excruciating detail. So how are you seeing the activity of the visual cortex? Can you provide any detail at all?

The suggestion that you're watching your own mental activity is the Cartesian theater in a nutshell, my friend. — NOS4A2

I'm not saying that I'm watching my own mental activity. I'm saying that the schizophrenic hears voices when his auditory cortex is active and even if he doesn't have ears, and that these voices he hears are mental phenomena. I'm saying that the synesthete can see colours in a dark room. I'm saying that those with cortical deafness don't hear anything even if their eardrums function normally. I'm saying that the flower might react to and move towards the light but it doesn't see or feel or hear the Sun. I'm saying that experience and its qualities are either reducible to or caused by complex neurological behaviour.

Right, you’re stuck in metaphor and analogy. You cannot describe perception without falling back on the first-person reports of medical conditions, genetic defects, sleep, and drug abuse, or wherever there is no evidence of any objects of perception at all.

It's not clear to me what you mean by perception...
Could you clarify? — Michael

That's a fair question, and I think the disagreement turns on a few distinctions that are easy to blur, so I'll try to make them explicit.

By perception I mean a non-inferential sensory openness by which an object is presented to a subject. By judgment I mean the act of affirming or denying that things are a certain way (“the apple exists now,” “the apple is red”). Perception is not itself a judgment, but it constrains judgment; inference is a further step where one belief is formed on the basis of others. So when I say perception does not proceed by inference from a surrogate, I mean that awareness of the apple is not achieved by reasoning from awareness of something else to the apple. When I say error lies in judgment rather than perception, I mean that perceptual presentation can remain world-anchored even when the judgment formed on its basis is false.

This helps with the slow-light apple case. If the apple disintegrates before the light reaches me, then the judgment “the apple exists now” is false. But that does not mean what is present to perception is a mental item or a memory. What is present is the apple’s visible presence at my location, carried by light. The light is not a third object perceived instead of the apple; it is the means by which the apple makes itself perceptually available across space and time. I am seeing the apple, but not the apple-as-it-exists-now. The mistake is one of temporal indexing at the level of judgment, not a loss of perceptual contact with the world.

This also clarifies the visor case. The point is not that the subject must consciously assess the visor’s accuracy. The point is structural: the epistemic warrant for beliefs about the distal object depends constitutively on the visor’s reliability. A visor produces a representation—an image whose correspondence to the scene is a further fact beyond what is perceptually given. Even if the subject is unaware of the visor, their access to the object is mediated by something whose correctness matters for warrant. That is why the perception is indirect.

This is what distinguishes visors from ordinary causal media like light, windows, or mirrors. Windows and mirrors can distort, but such distortions are typically perceptually available as distortions: a tinted window looks tinted, a curved mirror looks curved. They do not introduce a representational layer whose fidelity must be independently assessed in order for the object to be perceptually present. By contrast, a visor can systematically misrepresent without any perceptual cue that it is doing so. The difference is one of epistemic role, not degree of distortion.

That is why the question “when does mediation stop?” has no answer in terms of speed, distance, or number of causal links. Directness is not defeated by more mediation, but by a change in kind—from causal conduits that transmit an object’s own appearance to representational systems whose accuracy must be relied upon. Ordinary light propagation, reflection, and refraction do not play the latter role; visors, screens, and instruments do.

So the distinction I’m drawing is not a truism that would also accommodate a Cartesian theatre. The contrast is not between mediated and unmediated, but between non-inferential presentation of an object and awareness that depends on the correctness of a representational intermediary. That is the sense in which perception can be direct without being instantaneous, infallible, or free of causal structure.

It's not metaphor or analogy, just as "I feel pain" is not metaphor or analogy (which also doesn't require anything like a Cartesian theatre or a homunculus).

Directness is not defeated by more mediation, but by a change in kind—from causal conduits that transmit an object’s own appearance to representational systems whose accuracy must be relied upon. — Esse Quam Videri

So this is the exact naive realism that we discussed before. A thing's appearance, e.g. it's shape, orientation, colour, smell, taste, etc. is not something that is inherent in the object and then "transmitted" via some medium like light or vibrations or microscopic molecules in the air and into the phenomenal character of experience. To risk being overly reductive, there is just a collection of particles situated in space that interact with other particles in their immediate vicinity according to deterministic (or stochastic at the quantum scale) laws, which in turn interact with other particles in their immediate vicinity, etc., eventually interacting with the particles that make up someone's sense receptors and then the particles that make up someone's brain. The phenomenal character of experience (the appearance) is then either reducible to the behaviour of these brain-particles (if eliminative materialism is correct) or emerges from them. The suggestion that this phenomenal character — i.e. the "movements" of these particles — counts as the "direct presentation" of the “real” appearance of some distant collection of particles (but not any of the physically intermediate particles for some reason) makes no sense. That's just us naively projecting appearances out into the world, like a phantom itch.

I agree that concepts are involved in perception, and that classification is norm-governed and interest-relative. But concept-involvement is not the same thing as perceiving concepts. The fact that there is no sharp, language-independent cutoff for when a Sun becomes a non-Sun, or a seed becomes a tree, shows that our classificatory practices are vague, not that there is nothing mind-external there, or that persistence through change is merely linguistic. Ontological continuity and conceptual boundaries are different issues.

Direct Realism does not require that the mind-external world itself “decide” when something counts as a Sun or a tree. It requires only that there be mind-external continuants with causal powers, and that perception be directly related to those continuants, even though the concepts under which we describe them are supplied by us. So when I say that the Sun I perceive is a temporally extended continuant, I am not claiming that “Sun” is an ontological category written into the fabric of the universe, but that perception is directly related to a real, persisting physical system rather than to an inner representation.

The Presentism/Block Universe distinction doesn’t change this. On Presentism, what I perceive is a presently existing continuant whose earlier state is made perceptually available by presently arriving light. On a Block Universe view, what I perceive is a temporal part of an extended object. Either way, the object of perception is mind-external, not something that exists only in language or concepts.

This is also why the regress point still stands. If temporal mediation or vagueness in classification were sufficient to make perception indirect, then all perception would be indirect—not only perception of mind-external objects, but even the “direct perception” of mental images or sense-data, since those too are temporally extended, causally conditioned, and conceptually classified. In that case, perception itself could never get off the ground, because every purported object of awareness would require a further epistemic intermediary, generating an infinite regress. Any account of perception must allow something to count as non-inferentially present to the mind, or explanation never begins.

So the disagreement isn’t about whether concepts are involved (they obviously are), but about whether perception is fundamentally a relation to mind-external reality, or instead a relation to inner items plus inference.

Error arises when a judgment about the world fails to be satisfied by how things are, not when an inner experience mismatches an outer property. — Esse Quam Videri

Ok, fiar that's clearer. My objection then goes back to, how could we know unless we assume DR?

So the point isn’t that inversion is impossible or incoherent, but that it’s explanatorily idle with respect to the epistemic issues under discussion — even if it remains metaphysically possible. — Esse Quam Videri

Ok, fair enough - let's then just talk about colourblindness, which is extant rather than hypothetical. If the colourblind person judges what you see to be green as a red, what's the basis for calling that an error, in lieu of assuming DR?

Once truth and error are located at the level of world-directed judgment — Esse Quam Videri

This is what I'm having trouble with. There seems a huge leap being made to establish this - Part of hte IR commitment is that there isn't truly any 'error' in perception other than true hallucination. Even then, given it's not initiated by anything beyond the mind, 'error' is probably wrong. Its more the system drawing outside the lines. But that's a digression, so sorry if it distracts.

I've been trying to make this argument for a long time. Banno does a good job of using this to his advantage.

Perception is interpretive, mediated, and embedded in the world — and none of that entails indirectness. — Banno

I have my objections, but the position, i take it, is that the mediation is not manipulative or deceptive so gives a 'direct' indication of that object one has cast their eyes too.

I don't quite have an issue with this other than calling it direct. That seems patently unavailable to me, along your lines. The cat example you give later is a good one. Also, babies do not see colour the way they do later.

A description close to Davidson's anomalous monism, the view that while thoughts and actions are physically grounded (monism), there are not governed by strict laws. — Banno

I am sympathetic to his idea that there are no strict laws connecting the mental and the physical. I myself am incline to think the casual laws are descriptive and predictive but not so sure we should call them explanatory. If I watching a movie from a movie projector, can I come up with a casual law. Sure, I can cut a strip of film into sequential pieces and label them 1, 2, 3, and so on. The law is the previous number piece causes the next number piece, 1 causes 2, 3 causes 4 and so on. I can get another uncut strip of film of the same movie and make all kinds of predictions on what will follow when one sees any particular scene from the movie. But does this explain what the movie is about? What is the plot of the movie? What are motives of the character? What reasons are there that the story is set in that location?

Suppose in my mind I have the concept of something that I know as “cup”.

Suppose I perceive in my senses a single instantiation of this concept. — RussellA

Where does your concept of "cup" come from? How does your internal concept of "cup" instantiates in the external world?

I agree entirely with the scientific picture you sketch: perceptual experience is realized in neural processes, and physics describes only particles, fields, and causal interactions, not colors, shapes, or appearances as intrinsic properties of objects. Where I disagree is with the inference you seem to draw from this. From the fact that phenomenal character is neurally realized, it does not follow that perceptual content is therefore about neural states rather than mind-external objects. That inference presupposes an internalist bridge principle—roughly, that the physical realization of a state fixes its intentional object—which is a substantive philosophical thesis, not a deliverance of science.

I reject that bridge principle. On my view, appearances are not intrinsic properties transmitted from object to perceiver, nor are they mental projections; they are relational ways objects are perceptually available to situated perceivers under specific conditions. This does not require that anything like an appearance be “carried” through space as a non-physical property. It requires only that perceptual states be individuated in part by their relations to mind-external objects—by the causal and counterfactual dependencies that link those states to the objects they are experiences of. In that sense, perceptual content is world-involving rather than internally bounded: what the state is about is constitutively tied to the object, not merely causally downstream of it. Science tells us how perceptual states are realized and transmitted; it does not by itself determine whether their content is world-involving or confined to the head. That question is exactly what separates internalism from externalism, and it cannot be settled by physics alone.

it does not follow that perceptual content is therefore about neural states rather than mind-external objects — Esse Quam Videri

I didn't say that it's about neural states. I'm saying that phenomenal experience is neural states (or emerges from them). My concern is the relationship between these neural states and distal objects. There is certainly a causally covariant relationship, but nothing more substantial than that. The distal object and its properties are not "present" in the neural states, and nor does the distal object have a "real appearance" that is "transmitted" via light or vibrations and "into" these neural states.

I reject that bridge principle. On my view, appearances are not intrinsic properties transmitted from object to perceiver, nor are they mental projections; they are relational ways objects are perceptually available to situated perceivers under specific conditions. This does not require that anything like an appearance be “carried” through space as a non-physical property. It requires only that perceptual states be individuated in part by their relations to mind-external objects—by the causal and counterfactual dependencies that link those states to the objects they are experiences of. In that sense, perceptual content is world-involving rather than internally bounded: what the state is about is constitutively tied to the object, not merely causally downstream of it. Science tells us how perceptual states are realized and transmitted; it does not by itself determine whether their content is world-involving or confined to the head. That question is exactly what separates internalism from externalism, and it cannot be settled by physics alone. — Esse Quam Videri

All of which is consistent with the presence of a visor. If the phenomenal character of experience is not a "representation" of some supposed "real appearance" then a) what does it mean for the image on the screen to be an "inaccurate" representation of the distal object and b) why does it matter if it is? Either way, the phenomenal character of experience is its own thing. It just seems like special pleading when you previously said that light "transmits an object’s own appearance" but then argue that the the visor doesn't. What does light "succeed" in doing that the visor "fails" in doing?

Thanks, you've raised some good questions.

I’m not claiming that the mere fact that world-directed judgments can be true or false rules out inversion hypotheses, or renders them false. I’m happy to grant that spectrum inversion or other private aberrations remain metaphysically conceivable.

The claim is instead about explanatory role. Once truth and error are located at the level of world-directed judgment — governed by norms of use, correction, and responsiveness to the environment — inversion hypotheses no longer explain anything further about how perceptual judgments succeed or fail. They don’t add to our account of justification, error, or skepticism.

In particular, we don’t need to assume that colour is a property of objects or deny that assumption in order to make sense of perceptual error. Error arises when a judgment about the world fails to be satisfied by how things are, not when an inner experience mismatches an outer property.

Take colourblindness. We don’t identify error by checking whether the colourblind person’s experience matches ours or some phenomenal property in the object. We identify it through publicly accessible norms: stability across conditions, systematic correlations with wavelengths, successful coordination with others, and responsiveness to correction. The colourblind person’s experience is not incorrect — it’s simply different. What can be incorrect is the world-directed judgment when assessed within those shared practices.

Those norms are not arbitrary or merely conventional — they are shaped by, and answerable to, stable patterns of successful interaction with the world. But they are norms governing judgment, not standards for grading the intrinsic correctness of experience.

That’s why I say truth and error are located at the level of world-directed judgment. It’s not a leap so much as a refusal to start from the phenomenal-first picture that much of the traditional debate takes for granted. Once that picture is set aside, the notion of error no longer depends on assuming direct realism, but on the norms that govern our practices of saying how things are.