The difference between direct and indirect realists as represented in this thread, comes down to how we want to describe that perceptual relation. Is it between perceiver and a mental state? Or is it between perceiver and physical object? — frank

There is a relation between perceiver and physical object.

But there is no relation between perceiver and a mental state if the perceiver IS the mental state.

What does the Indirect Realist believe?

The homunculus infinite regress problem arises when the mind is assumed to be a separate entity to the brain, and the mind is looking at the neural activity in the brain.

When it is agreed that the mind is the neural activity in the brain, then this problem disappears.

John Searle pointed out the nature of identity in The Philosophy of Perception and the Bad Argument

The relation of perception to the experience is one of identity. It is like the pain and the experience of pain. The experience of pain does not have pain as an object because the experience of pain is identical with the pain. Similarly, if the experience of perceiving is an object of perceiving, then it becomes identical with the perceiving. Just as the pain is identical with the experience of pain, so the visual experience is identical with the experience of seeing.

What do words mean?

Wittgenstein’s “meaning is use” suggests that the meaning of a word is determined by how the word is used in language in a language game. Each language game exists within a “form of life”. A “form of life” means human activities within the world and social interactions between humans within this world.

Wittgenstein is presupposing a world. If there was no world then there would be no form of life and no language game.

So what is the meaning of the word “world”. On the one hand, its meaning comes from how it is used in the language game, but on the other hand, its meaning is presupposed in order to have a language game in the first place.

Therefore, its meaning cannot be found within the language game, as its meaning is presupposed in order to have a language game in the first place.

Then how can the meaning of the word “world” be found if not from the language game itself. Only within the philosophy of metaphysics.

Adding my tuppence worth.

I may regularly perceive in my mind a grey circle, which I infer to the best explanation has been caused by a regularity in the mind-external world

Such regularities of perceptions in the mind become concepts in the mind, where a concept is a regularity of perceptions in the mind.

Concepts, because they are regularities in the mind, may for convenience be given a name. The name is not important, but could be “bird”, for example.

The name “bird” therefore refers to not only i) a regularity of perceptions in my mind (aka concept) but also to ii) an unknown regularity in the mind-external world that causes such regularities of perceptions in my mind.

Such is the basic relation between concepts in the mind, naming in language and objects in the mind-external world.

I appreciate your feedback on my thesis.

3. Rejected: I would not claim that “content travels unchanged” through the chain. I would claim that perception is of the object via the chain, not that the chain preserves representational content. — Esse Quam Videri

You agree that the form of each link and the content of each link in the causal chain can change.

But all information about what initiated the causal chain must be contained within each link.

If both the form and content of each link can change, how exactly is this information about what initiated the causal chain expressed within each link?
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5. Rejected: This establishes at most epistemic underdetermination, not logical impossibility; the examples show fallibility, not impossibility.
6. Rejected: Fallibility or inferential uncertainty does not entail logical impossibility; this confuses limits on reconstruction with limits on knowledge. — Esse Quam Videri

As there is an arrow of time, there is an arrow of causation. We can remember the past but not the future.

During a game of snooker, we observe snooker balls at rest on a snooker table. It is logically possible using the laws of physics to determine the position of the snooker balls a moment in the future. However, it is logically impossible to determine the position of the snooker balls a moment in the past.

This is not epistemic undetermination, this is logical impossibility.
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7. Rejected: Non-sequitur. Even if causal origins cannot be reconstructed with certainty, it does not follow that the object of perception is an inner phenomenal item rather than the external object. — Esse Quam Videri

My argument in 1 to 9 is that causal origins cannot be reconstructed at all, not reconstructed with uncertainty.

How can causal originals be reconstructed even with uncertainty when you agree that not only the form but the content also of each link in the causal chain can change, especially when you accept 8.

8 - As an IR, I accept that it is not logically possible to know either the form or content of a prior link in the causal chain.
8. Granted.

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9. Rejected: False attribution. I do not claim we can logically reconstruct prior causal links; I claim that perception is world-involving without requiring such reconstruction. — Esse Quam Videri

How does the Direct Realist know what initiated the causal chain, if we only know about what initiated the casual chain because of the causal chain itself, and you agree that we cannot reconstruct prior causal links.

What else is there?

The capacity to experience colors and shapes is innate for people born with "normal" perceptual systems. But "yellow" and "circle" are more than just names, they are concepts that have to be understood through personal insight and stabilized through social practice. — Esse Quam Videri

We see the colour red when looking at a wavelength of between about 620nm to 750nm. We have the concept of the colour red through personal insight. We learn the word “red” through social practice.

As with the chicken and egg, which came first, i) we have the concept of the colour red through personal insight and then we learn the word “red” through social practice or ii) and we learn the word “red” through social practice and then have the concept of the colour red through personal insight?

I think i) is more reasonable.

John Searle in The Philosophy of Perception and the Bad Argument wrote about the identity between the perception and experience.

The relation of perception to the experience is one of identity. It is like the pain and the experience of pain. The experience of pain does not have pain as an object because the experience of pain is identical with the pain. Similarly, if the experience of perceiving is an object of perceiving, then it becomes identical with the perceiving. Just as the pain is identical with the experience of pain, so the visual experience is identical with the experience of seeing.

What the Direct Realist proposes is a logical impossibility

The bent stick argument is a weak argument against Direct Realism (DR), in that the Semantic Direct Realist (SDR) may sensibly say that although perception is indirect, cognition is direct. We directly cognise a straight stick that appears bent.

A better argument against SDR is that direct cognition is logically impossible.

The SDR agrees with the Indirect Realist (IR) that i) all our information about the mind-external world comes through our senses and ii) there is a temporal causal chain from something in the world initiating a causal chain which eventually causes a perception in the mind.

For example, we can conceptualise that the causal chain was initiated by the stick, followed by a wavelength of light, to an electrical signal in the optic nerve, then neural activity in the brain and finally perception in the mind.

The SDR agrees that the form of the links in the causal chain may change, for example, from a wavelength of light to an electrical signal. However, it is logically impossible for the content of the link not to change if the form of the link changes. From Leibniz’s Law, the Principle of Indiscernibles, two distinct things, such as two links of a causal chain having different forms, cannot share the same content, the same properties.

As the form of these links in the causal chain change, the content of these links must also change. But it is the content of these links that is cognised.

Therefore, the content of the link at initiation cannot be the same as the content of the link when perceived, but as it is the content that is directly cognised, what is cognised in the link at perception cannot be what would be cognised in the link at initiation.

The SDR is saying that in order to directly cognise the stick, even though the form of the links in the causal chain change, the content of the links must remain the same, as it is the contents of the links that is cognised, but this is a logical impossibility.

I don't deny the IR the right to believe these things, I only deny that they are rationally compelling. — Esse Quam Videri

That’s the question, which of IR and DR is more rationally compelling.
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Tensed truths are not only about the present, but about the past and future as well. Presentism doesn't rule out tensed truths about persistent objects. — Esse Quam Videri

I don’t understand how the Sun can persist through different times when in Presentism there is only one time, namely the present.

I can understand, however, that as a concept the Sun persists.
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I think that your account of experience, understanding and judgment is overly simplistic and elides many important distinctions. — Esse Quam Videri

Possibly, but this is a post on the Forum, not a PhD.
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For example, what does it mean to "perceive" the "combination" or "yellow" and "circle"? A "combination" is a relation. Are you saying we can perceive relations directly? — Esse Quam Videri

Are you saying that when you look at a table, you perceive the spatial relation between the table top and table legs indirectly?

Though I believe that there cannot be a relation in the absence of anything being related.
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"Yellow" and "circle" are classifications. Do these just "appear" within consciousness without any effort or learning on the part of the subject? — Esse Quam Videri

We need to learn the names "yellow" and “circle”, but I would have thought that our ability to perceive yellowness and circularity are innate, something we are born with.

This does not follow. You are trying to argue from epistemic limits to an ontological conclusion. Even granting the contestable claim that it is "logically impossible" to know what initiated the causal chain, all that follows is that we can't be certain of what we perceive. Fallibility doesn't imply indirectness. — Esse Quam Videri

A stick in water looks bent. The Semantic Direct Realist’s (SDR) position is that of indirect perception but direct cognition. The SDR is saying that in the mind-external world is a straight stick, and it appears bent. There are many instances of where perception is fallible.

The Indirect Realist (IR) is not saying that fallibility implies indirectness. The IR is saying that i) there is no stick in the mind-external world in the first place, ii) the fact there is no stick in the mind-external world is what implies indirectness, iii) the stick we perceive exists as a concept in the mind, not as a fact in the mind-external world.
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Persistence on Presentism is cashed out in terms of tensed truths and causal continuity, not simultaneous existence at multiple times. — Esse Quam Videri

The persistence of the Sun has a different meaning to the IR and DR.

For the IR, the Sun exists as a concept in the mind, and as a concept persists from the past to the present. This is reasonable.

For the DR, the Sun exists in the mind-external world. Accepting Presentism, an object cannot persist through different times when only one time exists. The tensed truth “The Sun exists now” is true now has no relation to “the Sun persists now”.

For the Sun to persist makes sense for the IR, but not for the DR.
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The causal chain doesn't interpose something between subject and object; it's the means by which the object is perceptually available. — Esse Quam Videri

As I see it:

I would appreciate it if sometime you could find any flaws in my main argument against Direct Realism (both Phenomenological Direct Realism (PDR) and Semantic Direct Realism (SDR)). — RussellA

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Judgment is the movement from sensory data to existential affirmation by way of insight and understanding, whereas inference is a movement from premises to conclusion by way of logical rules. — Esse Quam Videri

Suppose that many times I perceive the combination yellow circle.

Our ideas about the nature of a mind-external world is not subjective judgement alone, such as “we are a mind in a vat” nor objective inference alone, as we are reasoning about the subjective nature of the mind.

I both judge and infer that there must be a regularity in the mind-external world causing these regularities in my phenomenal experiences.

@Michael

I would appreciate it if sometime you could find any flaws in my main argument against Direct Realism (both Phenomenological Direct Realism (PDR) and Semantic Direct Realism (SDR)).

1 - Both the Indirect Realist (IR) and Direct Realist (DR) agree that there is something in the mind-external world that initiates a causal chain that eventually leads to a perception in our mind.
2 - The IR and DR agree that the links of this causal change chain may change in form, ie, from a wavelength of light to an electrical signal in the optic nerve
3 - The DR believes that a change in form of the link does not mean that the content of the link changes. IE, the DR believes that they still directly perceive what initiated the causal chain.
4 - The IR and DR agree that all our information about the mind-external world comes through our senses.

5 - My argument, as an IR, is that even if one knew one link in the causal chain, it is logically impossible to know either the form or content of a prior link. One can, however, infer to the best possible explanation.
For example, seeing a broken window, it is logically impossible to work backwards through a causal chain to know what initiated the causal chain and thereby know what broke the window.
Also, when a detective sees a crime scene, it is logically impossible for the detective to work backwards through a causal chain to know what initiated the causal chain and thereby know who committed the crime.
Also, when seeing snooker balls at rest on a snooker table, it is logically impossible to work backwards through a causal chain to know what initiated the causal chain and thereby know where the snooker balls were a moment earlier.
6 - Therefore, as it is logically impossible to know the form or content of a prior link in a causal chain, it is logically impossible to know what initiated the causal chain.
7 - But we do perceive things such as the Sun and a wavelength of light. As it is logically impossible to know what initiated the causal chain that gave us the information from the mind-external world, we cannot be directly perceiving what initiated the causal chain, whether the Sun or a wavelength. Therefore we can only be perceiving the phenomenal experience itself. From this phenomenal experience we can infer to the best explanation that in the mind-external world there is something we conceptualise as the Sun and wavelength of light.
8 - As an IR, I accept that it is not logically possible to know either the form or content of a prior link in the causal chain.

9 - The Direct Realist (both PDR and SDR) is basing their belief on a logical impossibility, that it is possible to know either the form or content of the prior link in a temporal causal chain.

I don't accept this phrasing "perceiving the Sun in the mind" if it implies that perception is of some sort of mental item.............................Likewise, I didn't accept this. It suggests that what is perceived is a mental item (a Sun-in-the-mind) and that perception involves matching that mental item to a worldly object. — Esse Quam Videri

The DR accepts there is a temporal causal chain from something in the mind-external world to their perception.

For example, we can conceptualise that the causal chain was initiated by the Sun, followed by a wavelength of light, to an electrical signal in the optic nerve, then neural activity in the brain and finally perception in the mind.

However, as all our information about the mind-external world comes through our senses, and as it is logically impossible to know the true nature of any link prior to coming through our senses, it is also logically impossible to know the true nature of what initiated any causal chain.

The DR agrees that they perceive a Sun because of a causal chain, but as it is logically impossible to know what initiated any causal chain arriving at our senses, what the DR is perceiving cannot be something in the mind-external world.

If the DR is not perceiving a “worldly object”, then they can only be perceiving something in their mind.
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Physical systems persist precisely by changing in structured ways. — Esse Quam Videri

I agree that the concept of a Sun is something that persists through time.

But how can something persist in a mind-external world, if persists means exists at different times, and in Presentism only one moment in time exists.
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DR doesn't require this. It requires only that perception be grounded in lawful causal dependence on the world. — Esse Quam Videri

I thought that DR requires that perception is grounded in a mind-external object. This mind-external object may in fact initiate a causal chain, but it is not the causal chain that the perception of the DR is grounded in.
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I think you are missing the point of the regress argument. At some point, something must count as non-inferentially present to the mind, or explanation never begins. — Esse Quam Videri

Do you mean that judgement is non-inferential?

In my sensations is a yellow circle. I judge that in the mind-external world is a Sun.

In what sense is judging that in the mind-external world there is a Sun different to inferring from my sensations that in the mind-external world is a Sun?

I agree that I am missing what other non-inferential thing must be present in the mind.

I think you are seeing two objects, not a single object. — Corvus

When I see a table, am I seeing one object, the table, or five objects, the table top and four legs?
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Objects exist in the external world if we can see and interact with them. — Corvus

I see an apple, touch it and see it move.

Both the IR and DR agree that there is a mind-external world of physical matter and energy that obeys the physical laws.

It is a problem of naming.

Suppose in touching the apple I knock off one atom. The apple has changed. Is it the same apple even though it has changed or should I give it a new name because it has changed.

If I give it a new name then it becomes a new object.

Only a human can decide whether it should keep its name or be given a new name.

Only a human can create new objects.

All this suggests that objects only exist in the mind and language, not in the external world.
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It needs explanation how brain generates mind, how brain is linked to mind or how mind works from brain. — Corvus

Very true.

(1) how persistence through time should be understood,
(2) how causation across time works, and
(3) what “direct” is supposed to contrast with in a theory of perception. — Esse Quam Videri

I will stick to Presentism, as this still makes my point.

The Indirect Realist (IR) and Direct Realist (DR) agree
1 - There is a temporal causal chain that follows the laws of physics from a mind-external something to perceiving the Sun in the mind.
2 - There is a mind-external world, and in this mind-external world physical matter and energy follow the laws of nature.
3 - In Presentism, only the present exists.
4 - There are objects such as the Sun

Beliefs of the IR and DR
1 - The Direct Realist believes that there is a one to one correspondence between the Sun we perceive in the mind to a Sun that both exists and persists in the world.
2 - The Indirect Realist believes that we do not perceive the mind-external world as it really is, but perceive it through a conceptual framework. For the Indirect Realist, the Sun is a concept that both exists and persists in the mind.

As there is an arrow of time there is an arrow of causation
1 - In the arrow of time, we can remember the past but not the future
2 - In the arrow of causation, given a present event, we can determine a future event using the laws of physics, but it is logically impossible to determine a past event.

In particular, during a snooker match, when all the balls are at rest, we can determine their immediate future positions using the laws of physics, but it is logically impossible to determine their immediate past positions using the laws of physics.

In general, during a snooker match, when all the balls are moving, we can determine their immediate future positions using the laws of physics, but it is logically impossible to determine their immediate past positions using the laws of physics.

Where does the Sun exist
Suppose what we know as the Sun in the mind-external world with the passage of time loses one atom. On the one hand, in the mind-external world there has been an ontological change. On the other hand, the human observer has the choice whether to keep the same name, the Sun, or change its name. As the Sun is generally accepted as a concept and within language, although there has been an ontological change, we keep the same name.

Suppose there is one object, an apple, and another object, a table, and the apple is on the table. We could name an apple on a table as “apptab”. We have thereby created another object, an apptab. In the same way we created the objects apple, table and Sun. All names are human creations and exist as concepts and within language.

Objects exist and persist through time because objects are names, and names exist and persist in concepts and language.

The IR and DR disagree
1 - The IR believes that objects such as the Sun only exist as concepts and in language, whereas the DR believes that objects such as the Sun exist in the mind-external world.
2 - The IR believes that we cannot know but can only infer a prior event in a temporal causal chain, whereas the DR believes that we can know a prior event in a temporal causal chain

On Presentism, to say that the Sun persists through change is not to say that past parts of the Sun still exist. It is to say that the present Sun stands in lawful causal continuity with earlier states. Persistence here is not identity-with-the-past, but continuity governed by physical laws. — Esse Quam Videri

As the Sun only exists as a concept and in language, it can persist through change both as a concept and in language. Something in the mind-external world that is constantly changing cannot persist.

Treating the Sun as a concept and in language is the position of the IR.

On Presentism, causal explanations are perfectly coherent: present states are effects of earlier states, even though those earlier states no longer exist. — Esse Quam Videri

Both the IR and DR agree that causal explanations are perfectly coherent and present states are effects of earlier states.

However, in a temporal causal chain, a future event can be determined from a past event using the laws of physics, whereas it is logically impossible to determine a past event from a present event using the laws of physics.

For the DR to believe that they can directly know a past event from a present event through a temporal causal chain is a logical impossibility.

This is why the regress point still matters. If the mere fact that a causal chain involves time were enough to make perception indirect, then your own claim that perception is “directly of something that exists in my present” would not stop the regress. That present item would itself be temporally conditioned, causally structured, and conceptually articulated, and so—by the same standard—would require a further intermediary. To halt the regress, something must count as non-inferentially present to the mind, and temporal mediation alone cannot disqualify it from playing that role. — Esse Quam Videri

As knowing a past event using a temporal causal chain is logically impossible, only by inference from the present can a past event be hypothesised. This is the position of the IR.

There is no non-inferential means of discovering a past event from the present using a temporal causal chain.

We are not interested in knowing it was a cup. We are interested in if the cup exists as a real object. — Corvus

The Indirect Realist does not believe that a cup exists in the mind-external world, but only exists in the mind as a concept. In the mind-external world exists physical matter and energy, which the human mind may interpret as being a cup.

The Direct Realist believes the cup exists both in the mind as a concept and as a real object in the mind-external world.

What makes something an object? Suppose we see an apple on a table. The apple is a single object. The table is a single object. But is the apple on a table a single object? There seems to be no reason to think so. But we could name an apple on a table “apptab”. Is the apptab now a single object just because we have given it a name?

This raises the question, do objects exist in the mind-external world or are they created by the mind?

Can you prove and demonstrate the existence of concept as arrangement of neurons in the brain? — Corvus

No. I assume the mind is no more than the brain, but others disagree.

But going back the DR or IR, they are both realism. Isn't realism about existence? — Corvus

Yes, both the DR and IR believe that a mind-external world exists. Even if there were no humans, there would still be a mind-external world.

It is not about concept, or knowing. It is about existence. — Corvus

Yes, even if there were no humans, there would still be a mind-external world. In this mind-external world there would be neither concepts nor knowledge.

Even if you don't have concept, you cannot deny what you are seeing in front of you - the cup shaped object, and it is real. — Corvus

I agree that even if I did not have the concept of “cup” I could not deny that in front of me I would still see shapes and colours.

But if I did not have the concept of “cup”, how could I know that what is in front of me is a “cup”? I would know something was in front of me, but I would not know that it was a “cup”

Both the DR and IR would agree that there is something in the mind-external world causing me to see something in front of me, and that something, whatever it is, is real.

Does existence of cup need concept of cup? — Corvus

That something in the mind-external world causing me to see something in front of me does not need any concept in my mind. That something exists independently of any concept in the mind.

What do you mean by existence? — Corvus

Something that is physical, being either matter or energy. Things in the world.

The neurons of the brain exist as matter and energy. My assumption is that concepts in the mind are no more than arrangements of neurons in the brain. In that sense, concepts also exist.

It seems to indicate that you don't need your internal cup in your mind to be able to see the external cup in the external world. — Corvus

No. I need the concept of a cup in my mind before I know I am looking at a cup. If I don’t know the concept of a cup, I don't know what I am looking at.

At the beginning first time you saw the cup, you didn't have the concept of cup, but you were still seeing it. After having seen the cup many times, you named the object "cup".
Would it be correct? — Corvus

No. I didn't see the cup many times, I saw many combinations of a square shape coloured cream, which I reasoned had been caused by something specific in the mind-external world.

From regularity of observation I learn the concept of a square shape coloured cream. For convenience this concept may be named, such as “cup”, but it could have been given any name.

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. — Esse Quam Videri

In Presentism, how can the Sun persist through change, when only the present moment in time exists. The Sun cannot exist in the past when the past does not exist.
In the Block Universe, in the present is a physical state of matter and energy and in the past is a different physical state of matter and energy. But you talk about the Sun persisting through change. If two physical states are different between the past and present, where is the commonality between them?

If the Sun loses one atom, why does it remain the Sun rather than become a different object?=========================

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. — Esse Quam Videri

How can the Sun persist through time?
In Presentism, how can that part of the Sun that existed in the past and no longer exists in the present directly causally affect the present? Indirectly, yes, but directly, no.
In the Block Universe, how can that part of the Sun that exists in the past causally affect anything in the present, when in a Block Universe all moments in time are fixed, and there is no movement between moments in time?

As regards language, in what sense does the past directly (rather than indirectly) affect the present?=====================

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. — Esse Quam Videri

In Presentism, what I see in the present was indirectly caused by something in the past, but that something in the past no longer exists, so I cannot directly perceive it.
In a Block Universe, nothing can move between the past and present because both the past and present are fixed, including perception of the past from the present.

For both the Indirect and Direct Realist, the mind-external exists, and being mind-external, not just something that exists only in language or concepts. =================================================

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. — Esse Quam Videri

As regards temporal causal chain:
In Presentism, we infer that there is a temporal causal chain from a mind-external something in the past to a perception in the mind in the present. We can only directly perceive the present as the past no longer exists.
In the Block Universe, both the past and present are fixed, meaning that at each moment in time perception can only be directly of that particular moment in time .

As regards language:
In Presentism, only the present exists, and in the present I have the concept of the Sun, meaning that my perception can only be directly about something in the present.
In a Block Universe, each moment of time is fixed and nothing moves through this Block Universe, meaning that at each moment in time the perception of a concept can only be directly in that particular moment in time.

When I see the Sun, my perception is directly of something that exists in my present. There is no regress if my perception is directly of something.

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

Suppose on many different occasions I see the same combination of things, such as a square shape being cream in colour. Using my reason I can infer that in the mind-external world something exists that is causing me to see this particular combination of square shape being cream in colour. I don’t know what this something is in the mind-external world, but for convenience I can give it a name, and I name it “cup”. I could have named it anything, but I happen to name it "cup".

Therefore my concept of “cup”, a combination of a square shape being cream in colour has come from regularly seeing the combination of a square shape being cream in colour.

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?

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.

I recall an argument from somewhere that argued something to the effect of: — Michael

Absolutely.

Linguistically, I could call an animal with a long proboscis, tusks, large ear flaps, pillar-like legs, and tough but sensitive grey skin a “giraffe”, but this is a misuse of language. Similarly, the Direct Realist’s argument that they perceive mind-external objects “directly”.

Yes, and logically, how is it possible to “directly” perceive a mind-external object in the night sky, such as a star, when that star may in fact no longer exist.

It only makes sense that the direct object of our perception and cognition exists in our mind, from which we may reason and indirectly infer its cause as a mind-external object. The Indirect Realist does believe in a mind-external world, hence the name “Realist”. For me, my intellectual rather than instinctive belief in a mind-external world comes from “inference to the best explanation”, gaining understanding about the mind-external world indirectly.

From the fact that perception is causally mediated and temporally downstream, it does not follow that the object perceived no longer exists, nor that what is perceived is a memory or an illusion. — Esse Quam Videri

It depends what you mean by “the object perceived no longer exists”.

Light takes 8 min 20 sec to travel from the Sun to the Earth. The Sun we look at now in the present is not the same Sun as it was in the past 8 min 20 sec ago. The Sun is continually changing.

It depends whether you are referring to the object as a concept, such as the concept of a Sun, in which case we do have the concept of the Sun as it existed in the past, exists in the present and will exist in the future. This is the position of the Indirect Realist, in that the Sun exists as an object as a concept in the mind in the present.

Or are you referring to the object as a particular instantiation, such as a particular temporal instantiation of the Sun, in which case the Sun we are looking at in the present is not the same Sun as the Sun that existed in the past. And if so, it becomes impossible to directly look at any mind-external object, because a mind-external object is something that no longer exists in the present. But this is the position of the Direct Realist.
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So at this point, the disagreement is no longer about logic or semantics, but about whether temporal causation entails that the object of perception must be a present mental item rather than a mind-external object. — Esse Quam Videri

One aspect is semantics, the normal use of language. When reading about Caesar, it would be misleading to say that we have direct knowledge that Caesar crossed the Rubicon. When looking at evidence of a crime, it would be misleading for the detective to say that he has direct knowledge of the criminal. Similarly, it is misleading to say that we have direct knowledge of a mind-external object, when we only know about the mind-external object because of a temporal causal chain.

Another aspect is logic. How can our perception of something in the present give us direct knowledge of something that happened in the past, when that something that happened in the past no longer exists in the present. How can we have direct knowledge of something that no longer exists.

By contrast, the premise “the mind is only directly aware of the senses” is not a law of logic; it is a substantive epistemological thesis. — Esse Quam Videri

I agree that my premise was wrong.

I am using perception in the sense of cognition, rather than seeing.

We need premises that the IR and DR can agree on, such as:

There is no absolute definition of a word, such as direct or indirect, but usage should be normative within language.
There is a mind-external object.
An object is perceived by the mind.
We can have many different types of perceptions about a mind-external object, such as sight, sound, touch, taste, feel, smell, but all these perceptions are mediated by our senses.
There is a causal chain from the mind-external object to the object perceived in the mind.
The links in the causal chain are of a different kind, in that the perception of a colour in the mind is of a different kind to the neural activity in the brain, is of a different kind to the electrical signal in the optic nerve and is of a different kind to the wavelength of light between the eye and the mind-external object.
The senses mediate between the object perceived in the mind and the mind-external object.
We are not perceiving the links of the chain, we are perceiving the content of the links as an object.
The perception of the object and the links in the causal chain have been caused by the mind-external object.
The links in the causal chain are temporal, in that each link has been directly caused by the previous link.
I cannot directly perceive the cause of a link, as the cause of each link is temporally prior to the link.
Only the present time exists. Therefore, I can only directly perceive the present time and my memories of the past. Therefore, I can only indirectly perceive the past.
The DR believes that they directly perceive an object, and the object they perceive is the same object as the object in the mind-external world.
The IR believes that they directly perceive an object, but there is no reason to think that the object they perceive is the same object as the object in the mind-external world.

Therefore:

As I can only directly perceive the present, any object I perceive must exist in the present. An object can only exist in the mind in the present as a memory.

Therefore, I cannot directly perceive the mind-external object, as the mind-external object was at the beginning of a temporal causal chain, and I cannot directly perceive something that was in the past.

I can say that I have direct cognition of the object because the object that I am directly cognizing is in the present and in my memory. I have indirect cognition of the mind-external object because I cannot have direct cognition of the past.

When I cognize about a mind-external object in my mind, I am cognizing about something that no longer exists, and because it no longer exists, is now an illusion.

I think this makes the disagreement very clear, and it turns on a specific claim you’re making: that it is logically impossible for the human mind to directly know how things are in a mind-external world, because everything we know comes through the senses. — Esse Quam Videri

Your reply gives me plenty of food for thought.

Yes, I am saying that it is logically impossible for the mind to directly know how things are in a mind-external world, whereas you propose that the Direct Realist says that it is possible for the mind to directly know how things are in a mind-external world.

Perhaps it comes down to whether one accepts the rules of logic or not. I agree that logic is beyond justification.

For example, either one accepts the Law of Identity or one doesn’t. No amount of argument is going to prove that “whatever is, is”. No amount of argument is going to prove the Law of Contradiction, “nothing can both be and not be.' No amount of argument is going to prove the Law of Excluded Middle, that “Everything must either be or not be.' Logic is beyond explanation, It is something one either accepts or doesn’t accept.

Taking another example, the premises "Mars is red" and "Mars is a planet" support the conclusion "Mars is a red planet". The premises “the mind is only directly aware of the senses” and “the senses mediate between the mind and the mind-external world” support the conclusion "the mind cannot be directly aware of a mind-external world”.

Yes, it may be that the Direct Realist does not accept the logic that the mind cannot be directly aware of a mind-external world, but no amount of argument is going to persuade them otherwise.

A sensation can prompt, occasion, or constrain a judgment, but it is the judgment that takes responsibility for saying how things are and can therefore be assessed as correct or incorrect. — Esse Quam Videri

There are two aspects to sensations and being truth-apt.

If I perceive a bent stick, then it is always true that I perceive a bent stick, therefore not truth-apt.

But if I perceive a bent stick and that is not how things are in the world, then it is not true that if I perceive a bent stick then in the world there is a bent stick. This is not a judgement. This is about how things are in the world. Perceptions can be truth-apt independent of any judgments made about them.

I can then make the judgement that “if I perceive a bent stick then in the world there is a straight stick”, and this judgement is certainly truth-apt.

As regards epistemic role, not only does a sensation take a responsibility in being about how things are or are not in the world but also judgement takes a responsibility in arriving at a proposition that is either true or false.

I think what’s really at issue here is how we understand truth and directness. On my view, truth doesn’t consist in a resemblance or mirroring between what’s in the mind and what’s in the world, but in a judgment’s being correct or incorrect depending on how things are — Esse Quam Videri

Basically the choice between Indirect Reason and Direct Reason.

The question is, is it logically possible for the human mind to know “how things are” in a mind-external world.

Everything the human mind knows about the mind-external world comes through the five senses, meaning that it is logically impossible to know about the mind-external world independently of the human senses.
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I realize this may sound like I’m simply assuming that judgments can be answerable to the world, but every account of truth has to take something as basic; — Esse Quam Videri

You are assuming the human mind can know about the mind-external world, but how is this logically possible? How is it possible to know what broke the window just by looking at the window? How is it possible to know the cause of our sensation of the colour red just from the sensation itself?

I directly perceive the colour red in my senses.

I reason about a causal chain that has caused my perception, such that in the world is a wavelength of light that enters my eye, and travels up my optic nerve as an electrical signal to arrive at my brain which I then perceive as the colour red.

I know my perception of the colour red directly. I know about the wavelength of light indirectly by looking at the display on a spectrometer. I know about the electrical signal indirectly by looking at the display on an oscilloscope.

Therefore, I only know about the wavelength and electrical signal indirectly by looking directly at a screen. This means that all my direct knowledge is visual, and from this direct visual knowledge I can indirectly reason about the causal chain.

From my direct visual knowledge of my perception of colour and directly looking at the screen of an spectrometer and oscilloscope I can indirectly reason about the causal chain that caused my perception of the colour red using “inference to the best explanation”.

It is logically impossible to directly know the cause of what I perceive, although I can indirectly reason about the cause of what I perceive.

The Indirect Realist uses “inference to the best explanation” to indirectly reason about the mind-external world.

The Direct Realist mistakenly believes that they can directly know the cause of an effect. They believe that they can directly know the cause in the mind-external world of their perceiving the colour red in their mind. Yet for the mind to directly know the mind-external is a logical impossibility.

We can indirectly infer using reason “how things are” in the mind-external world, but it is a logically impossibility for the human mind to directly know “how things are” in the mind-external world.

I mean something closer to this: when we make judgments, we are implicitly adopting standards of correctness (e.g. truth, evidence, coherence, reasonableness). — Esse Quam Videri

The word "judgment" means deciding what is true or false. What is true or false means being answerable to how things are.

In this sense, yes, as definitions can be normative, judgement is here a normative definition.
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That is why judgments — not sensations — belong in the space of reasons. — Esse Quam Videri

Reason could not exist without sensations. The very existence of reason depends on sensations. I can only reason “if I see a red screen in my mind then there is a red screen in the world" if I have the sensation “I see a red screen”.
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Sensation constrains judgment, but it does not itself enter into justification or inference. — Esse Quam Videri

It depends what you mean by “enter into”.

A judgement could not exist without sensations. The very existence of a judgement depends on sensations. I can only judge “if I see a red screen in my mind then there is a red screen in the world" if I have the sensation “I see a red screen”.

When looking at either a ship or a photograph of a ship, both the Semantic Direct Realist (SDR) and Indirect Realist agree that perception is indirect through a causal chain and cognition direct.

Where the SDR and Indirect Realist disagree is where this directly cognized ship exists.

The Indirect Realist believes that the ship they perceive exists in the mind as a particular instantiation of their concept of ship, caused by something that exists in a mind-external world that is unknown.

The SDR believes that the ship they perceive exists in the mind as a particular instantiation of their concept of ship, caused by something that exists in a mind-external world that is the same as what they perceive in their mind.

So in the mind of the SDR is something that weighs 10,000 tonnes, is 200m long, 25 m wide and 30m tall. But this is obviously not the case.

The SDR says that they are directly cognizing the ship in the mind-external world, but if in the mind of the SDR there is no direct cognition of a weight of 10,000 tonnes, length of 200m, width of 25m and height of 30m, then what exactly is the SDR directly cognizing? The idea of a ship?

My claim was not that single judgments are reliable, infallible, or likely to be correct. Epistemic authority is not a matter of probability, reliability over isolated cases, or confidence in one-off judgments. It concerns what kind of act is even eligible to be assessed as correct or incorrect at all. — Esse Quam Videri

Based on the Merriam Webster Dictionary, normative means conforming to norms, and norms means a principle that ought to be followed.

I agree that humans ought to be continually making judgements, such as “if I see an orange screen in my mind then there is an orange screen in the world”.

You use the word “authority”. A judgement cannot give itself authority. Any authority must come from outside the judgement. By what authority ought I to be continually making judgments? Where does this authority come from? What gives me the authority to make judgments?
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Sensation, as you agree, is not truth-apt. Judgments are. — Esse Quam Videri

As you say, a sensation cannot be wrong, is not truth-apt, but a judgement can be wrong, is truth-apt.

Surely, If we are looking to an authority, we would prefer an authority that cannot be wrong, such as the senses, rather than an authority that is more often than not wrong, such as a judgement.

That I see an orange screen in my senses is authoritatively foundational to my subsequent reasoning, yet my judgement that “if I see an orange screen in my mind then there is a green unicorn in the world” has no authority in my reasoning about the world.
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Likewise, the normativity I’m invoking is not the moral norm “you ought to judge,” — Esse Quam Videri

Is not the normal use of the word “normative” a moral norm, such as “you ought not smoke”
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Epistemic authority lies in judgment because judgment alone is answerable to truth — even when, and especially when, it turns out to be wrong. — Esse Quam Videri

The problem is we give no authority to a judgement just because it is a judgement. We give authority to the content of a judgement.

For example, we give no authority to the judgement that “if I see an orange screen in my mind then there is a green unicorn in the world” just because it is a judgement. We give authority to the content of the judgement.

That is also why sensory experience, while indispensable, cannot itself function as an inferential premise. Sensation is not the kind of thing that can be right or wrong. Judgment is. And that difference is where epistemic authority resides. — Esse Quam Videri

It is possible to infer from a single sensory experience, such as “I see an orange screen”, what exists in a mind-external world, but the probability of being correct is remote.

It is also possible to commit oneself to the judgement that “if I see an orange screen then there is an orange screen in the world”, but again the probability of being correct is remote.

I agree that a sensory experience is not truth-apt whilst a judgement is.

As it is unlikely that any inference from a single sensory experience will be correct, it is also unlikely that any single judgement will be correct either.

There is the normative claim “you ought not to be smoking”

There is also the normative claim “I ought to commit myself to making a judgement". I agree that it is not the content of the judgement that is normative but rather the act of committing oneself to making a judgement that is normative.

However, a judgement being normative does not make it any more likely to be correct than a descriptive judgement. There is no reason why a normative judgement that one is committed will be more correct that a descriptive judgement one is not committed to.

Epistemic authority resides neither in a single sensory experience such as “I see an orange screen” nor in a single normative judgement, such as “I ought to commit myself to making a judgement".

We must look elsewhere for epistemic authority.

First, when I speak of normativity, I am not talking about moral norms (e.g. “evil is bad”), but epistemic normativity: truth, falsity, correctness, and justification. To make a judgment is to take on a set of epistemic responsibilities. That normativity is constitutive of judgment, not something inferred from experience or imposed by the will, and it is independent of any moral “ought”. — Esse Quam Videri

Suppose you make the judgement that if you see an orange screen in your mind then there is an orange screen in the world.

Your judgement is true if when you see an orange screen in your mind then there is an orange screen in the world.

What makes your judgement normative rather than descriptive?

In society, the rule “you should not smoke indoors” is normative because it is controlled by the law.

In life, the rule “evil is bad” is normative because it is part of an innate, human nature.

You say your judgement is not normative because of any phenomenal experiences or will of the mind.

Then what exactly makes your judgements normative rather than descriptive?

The indirect realist sees the causal chain and says that perception is indirect. The direct realist sees the chain and point out that the chain is how we know about the ship. — Banno

The indirect realist reads the book The Republic by Plato and says that our knowledge about Socrates is indirect. The direct realist reads the book and says that the book is how we know about Socrates.

Both are true.

Our knowledge about the ship is indirect because it has come directly from the causal chain.

The indirect realist is referring to the ship. The direct realist is referring to the causal chain.

Your reply nicely clarifies the remaining disagreement. — Esse Quam Videri

I may perhaps now understand your position.

Rationalism vs Empiricism

In the grand debate between Rationalism and Empiricism, I would tend to position myself with the Empiricists, such as Hume, where knowledge comes from a combination of sense experience and a reflection on such sense experiences.

I am thinking that you would position yourself with the Rationalists, such as Descartes, where there are significant ways in which our knowledge is gained independently of sense experience.

Nothing is fixed, but the Rationalists tend to align themselves with Direct Realism, as they propose a direct relationship with the world through reason, and the Empiricists tend to align themselves with Indirect Reason, as they rely more on sensory input (SEP - Rationalism vs Empiricism)

However, in that nothing is fixed, I also support Kant’s attempt to bring Rationalism and Empiricism together through Transcendental Idealism.

Evil is bad

As an empiricist, I would tend to judge that “evil is bad” from observations of the world, whereas, as you say, such a judgement should be the normative “I ought to judge that evil is bad” independent of any observations of the world.

I agree that such a normative judgement does not infer Idealism.

Epistemic norms are conditions for the possibility of inquiry, not constituents of reality. To say that judgment is norm-governed independently of experience is not to say the world is mental, but that knowing has irreducible normative structure.@Esse Quam Videri

The empiricist would tend to the belief that from observing that evil is bad, their descriptive judgement would be that evil is bad.

The rationalist would tend to the belief that an observation of evil must be bad, because their normative judgement is that evil is bad.

The difference is a direction of fit: the empiricist from the world to the mind, the rationalist from the mind to the world.

Orange screens

The empiricist would tend to the belief that when I am seeing orange in my mind then I can infer that there is an orange screen in the world, and then make the descriptive judgement that “I am seeing orange in my mind because there is an orange screen in the world”

The rationalist would tend to the normative judgement that because “I ought to be seeing orange in the mind because there is an orange screen in the world”, then when I am seeing orange in my mind then there should be an orange screen in the world.

As you say, "That is where we part ways."

But inference requires propositional, truth-apt premises. — Esse Quam Videri

I agree.
The major premise is the judgement = the screen is orange in the world if I am seeing orange in my mind.
The minor premise is the senses = I am seeing orange in my mind.
The conclusion is the inference = the screen is orange in the world.
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That leaves you with a dilemma:
If “I am seeing orange” is truth-apt, then it is already a judgment and your staged model collapses.
If it is not truth-apt, then it cannot function as a premise, and the claim that stage-three judgments are inferred from it does not follow. — Esse Quam Videri

The minor premise “I am seeing orange” is not truth-apt. The major premise is truth-apt.
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This is why I’ve insisted that perceptual judgments are not inferred from sensory contents — Esse Quam Videri

I agree.
The perceptual judgement that the screen is orange in the world is inferred from both sensory content in the mind, I am seeing orange, and the judgement in the mind that “if I am seeing orange in my mind than the screen is orange in the world”
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On my view, representation, truth, and epistemic authority belong at the level of judgment, not sensation. — Esse Quam Videri

As regards representation, the orange I see in my mind represents the screen being orange in the world. As regards truth, my judgement that "if I am seeing orange in my mind then the screen is orange in the world" is true if the screen is orange in the world
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o the issue isn’t whether the senses mediate our contact with the world — I agree they do — but whether that mediation is inferential and representational, or whether judgment is norm-governed and answerable to how things are without being derived from inner items. That is the point at which we diverge. — Esse Quam Videri

I judge evil to be bad because of what I observe in a mind-external world

The normative I ought to judge that evil is bad Is made prior to any observations of a mind-external world, which still suggests Idealism.

Sensory experience supplies data that constrains inquiry, but it does not supply premises from which judgments about the world are inferred. — Esse Quam Videri

Inferences

I see a wet umbrella and infer that it is raining outside. In my senses I am seeing orange and infer that in the world the screen is orange.

I see a wet umbrella and I am seeing orange are conceptual, because both umbrella and orange are concepts.

They are neither truth-apt nor judgements, because if I see a wet umbrella then I see a wet umbrella, and if I am seeing orange then I am seeing orange.

It is raining outside and the screen is orange are truth-apt, because either they are true or they are false. It may be that I see a wet umbrella and it is not raining outside. It may be that I am seeing orange and the screen is not orange.

Premises
Major premise - all humans are mortal
Minor premise - Socrates is human
Conclusion - Socrates is mortal

Major premise - Umbrellas get wet in the rain
Minor premise - I see a wet umbrella
Conclusion - it is raining

Major premise - the screen is orange if I am seeing orange
Minor premise - I am seeing orange
Conclusion - the screen is orange

The major premise is the judgement in the mind using reason, and is truth-apt.
The minor premise is what I sense, and is not truth-apt.
The conclusion is a state of affairs in the world, which may or may not obtain as a fact, and so is truth-apt.

Inference requires premises that are truth-apt — Esse Quam Videri

I agree. In order to infer from seeing orange in my senses that the screen is orange in the world, I need to have the major premise “the screen is orange if I am seeing orange”, which is a judgement based on reason, and is truth-apt

So either stage two is truth-apt, in which case it already is a judgment and your staged model collapses, or it is not truth-apt, in which case the claim that stage-three judgments are inferred from it does not follow. — Esse Quam Videri

In stage two of perception, I am seeing orange in my senses. This is not truth-apt, because if I am seeing orange then I am seeing orange.

My judgement that “the screen is orange if I am seeing orange” is my major premise, and is truth-apt, in that the premise may be true or false.

If I am seeing orange in my senses, and have judged that “the screen is orange in the world if I am seeing orange in my senses”, then I infer that the screen is orange in the world.

What I deny is that mediation entails inferential grounding. — Esse Quam Videri

Seeing orange in my senses mediates between my judgement “the screen is orange in the world if I am seeing orange in my senses”, and my inference that the screen is orange in the world.

In this sense, mediation plus judgement is the ground for inference.

The epistemic work is done at the level of judgement itself, not by moving outward from inner representations. — Esse Quam Videri

Judgement by itself is insufficient to know anything about any mind-external world. The judgement “the screen is orange in the world if I am seeing orange in my senses” tells us nothing about any mind-external world.

If I am seeing orange in my senses then, if my judgement is true, the screen is orange in the world.

As the word “house” in language represents a house in the world, my seeing orange in my senses represents an orange screen in the world. A representation links the mind to any mind-external world.

The epistemic work is achieved by judgements about our sensations, which, if true, enables the mind to represent any mind-external world.

So the disagreement isn’t about whether the “bridge of the senses” must be crossed — it’s about what crossing that bridge amounts to: inferential reconstruction from inner items, or norm-governed judgment constrained by experience but not inferentially derived from it. — Esse Quam Videri

From observing many phenomenal experiences I can derive judgements, such as “the screen is orange in the world if I am seeing orange in my senses”. From the principle of “Confirmation Holism”, each judgement must be supported by other judgements in a coherent whole. If my judgements do become part of a coherent set of judgements, then my confidence in each judgement will necessarily increase. All these judgements require the mediation of the senses. All these judgements require “the bridge to be crossed” if any are to have any validity.

There are no normative judgements about what ought to be independent of phenomenal experiences in the senses. My judgement that “the screen is orange in the world if I am seeing orange in my senses” finds its justification in “Confirmation Holism”, where each judgement must be supported by other judgements in a coherent whole. My judgement that “the screen is orange in the world if I am seeing orange in my senses” cannot find its justification as a normative “because it ought to be”.

However, I can understand that normative judgements of what ought to be could exist within Idealism, where reality is a mental construct and there is no mind-external world. Where reality is a mental construct, then we could construct normative judgements about what ought to be.

I can only speak for myself on this, but I do not reject the idea that knowledge is mediated by the senses. — Esse Quam Videri

To my understanding of perception:

Stage one is the mental, introspective, singular, particular phenomenal experience in the senses when the eye is directed at a wavelength of say 630nm. This is neither conceptual nor truth-apt. As you say, it is not a normative act.

The key issue here is that sensation is not a normative act. This means it is not conceptual and is not truth-apt – it is simply not the kind of thing from which the rest of our knowledge could be inferred.@Esse Quam Videri

Stage two is the introspective awareness that “I am seeing orange”. This is conceptual, as “orange” is a concept. This is not truth-apt, and therefore not a judgement, because if I see orange then I see orange. Stage two is not an introspective judgement.

That’s not to say that we can’t make judgments about sensory content – we can (“I am seeing red”) – but this is not what we ordinarily mean by the word “perception”. Instead, this is a reflexive, second-order kind of judgment more commonly referred to as “introspection”.@Esse Quam Videri

Stage three is the introspective judgement that “the screen is orange”. Such a judgement is conceptual, because “screen” is a concept. The judgement is truth-apt on the assumption that there is a mind-external world where there are such things as screens. “The screen” is referring to something mind-external. I agree that introspective judgements about something mind-external are constrained by sensory content, but disagree that they are not inferred from sensory content. How can we get knowledge about any mind-external world if not from our sensations? What other way is there to get knowledge about a mind-external world if not from our sensations?

By contrast, judgment is conceptual and truth-apt. The act of judgment is part of the norm-governed process of inquiry. So, while judgments are constrained by sensory content, they are not inferred from sensory content. As we argued above, this would be impossible.@Esse Quam Videri

The only information we have about any mind-external world is through our five senses. Therefore our perceptual judgement that “the screen is orange” of logical necessity must be based on our sensations. I agree that we are not making any judgement about the sensory content “I am seeing orange”, because no judgement is needed to know that “I am seeing orange”. But we are making judgements about what the sensory content represents, in that we are judging by inference that “I see orange” in the mind represents in a mind-external world “the screen is orange”. We can only make judgements about things in any mind-external world by inferring from sensory content in the mind.

When we make perceptual judgments we are not making judgments about sensory content. We are making judgments about things in the world (“there is a ship”).

I agree that epistemic authority belongs to judgement about how things actually are. Judgement exists in the mind and how things actually are exists in a mind-external world. Between the mind and a mind-external world are the five senses, meaning that if we are to know anything about a mind-external world it is inevitable that the bridge that is our senses must be crossed.

but epistemic authority belongs to judgment, which is governed by norms of sufficiency, relevance, and answerability to how things actually are.@Esse Quam Videri

From what you say, if there is no need to cross the bridge of our senses, this suggests to me that your position is that of Idealism. There are many kinds of Idealism, but fundamentally, Idealism asserts that reality is entirely a mental construct, which is also why you don’t support the realism of either the direct or indirect realist.

Once that distinction is in view, the need to “bridge” phenomenal experience via IBE (inference to the best explanation) largely dissolves.

I’ve also acknowledged that my own view does not count as traditional naïve realism. My point is that it does not count as traditional indirect realism either.@Esse Quam Videri

All of this is presented as implicitly rejecting the idea that meanings are fixed by hidden reference-makers (phenomenal or physical), and treating meaning instead as constituted by the public criteria governing a word’s use within a practice. — Hanover

Where is the meaning of a word fixed?

Each individual has five senses. All information about anything external to the individual can only pass through the individual's five senses.

The Direct Realist believes each individual has direct cognition of a public sphere with its public language game. The Direct Realist believes that such a public sphere exists independently of any mind.

The Indirect Realist believes that each individual can only infer such a public sphere by reasoning about experiences perceived in their five senses.

Therefore, for the Direct Realist, meaning is fixed in a public sphere independent of any mind. For the Indirect Realist, meaning is fixed in each individual’s mind by reasoning about experiences perceived in their five senses.

Your view seems to reject the representational aspect while still treating experience as epistemically primary, whereas I would want to reject both. — Esse Quam Videri

As an Indirect Realist, it would be illogical to reject any representational aspect, and not sensible not to treat phenomenal experience as epistemically primary.

My understanding is that:

The Indirect Realist avoids external world scepticism by deriving concepts based on consistencies in these phenomenal experiences. Using these concepts, which can represent, the Indirect Realist can then rationally employ "inference to the best explanation” to draw conclusions about an external world causing these phenomenal experiences.

It can be said that there are three temporal stages in perception.

Stage one. Phenomenal experiences, such as when we look at a wavelength of 736nm
Stage two. Mental concepts based on phenomenal experiences, such as perceiving red light
Stage three. Judgements about what these concepts represent, such that red light represents stop.

Sense data is introduced at stage two. As Betrand Russell wrote in The Problems of Philosophy:

Let us give the name of "sense-data" to the things that are immediately known in sensation: such things as colours, sounds, smells, hardnesses, roughnesses, and so on. We shall give the name "sensation" to the experience of being immediately aware of these things .... If we are to know anything about the table, it must be by means of the sense-data - brown colour, oblong shape, smoothness, etc. -which we associate with the table.

It is in the nature of a judgement in stage three that any judgement could be wrong. This is why it is called a judgement. To negate all judgements because one judgement might be wrong would be to contradict the very meaning of the word.

All three stages are essential to both Indirect and Direct Realism.

As regards stage one, without phenomenal experiences, humans would be imprisoned in a dark and soundless room. As regards stage two, without the prior concept of ship, when looking at the singular instantiation of an object, no one would be able to say “I see a ship”. As regards stage three, no one would be able to judge that a set of perceived concepts represents a ship.

There is phenomenological Direct Realism (PDR), direct perception and direct cognition, and Semantic Direct Realism (SDR), indirect perception and direct cognition.

I would imagine that most Direct Realists on this thread believe in SDR, as few would not admit that when we see a ship we directly see the light entering the eye from the ship, in that, as has been said, we don't directly put our eyeball on the ship.

Both the Indirect Realist and SDR can say “I see a ship”, even though for both it is through the intermediary of light entering the eye, and for both illusions and hallucinations are possible. The linguistic expression “I see a ship” as part of a communal language can be understood by all those using the same language game, regardless of any metaphysical implications. If pressed, the IR may say “I see the wavelength of light as a ship” and the SDR may say “I see a ship by means of a wavelength of light”, but for convenience, to say “I see a ship” is perfectly understandable.

The Indirect Realist and the SDR differ in that the SDR believes that their judgements can transcend their phenomenal experiences, whereas the Indirect Realist doesn’t.

Between the mind and any external world are the five senses. The mind only knows what passes through these five senses. Therefore, for the Indirect Realist, anything we think we know about any external world comes indirectly from “inference to the best explanation”. However, for the Direct Realist, we are able to transcend these five senses and directly know about any external world.

One question for believers in SDR is how they explain their judgements are able to transcend their phenomenal experiences

Yes, that’s broadly how I see it. Phenomenal experience is particular and non-conceptual, and for that reason it isn’t the kind of thing that can represent the world accurately or inaccurately. — Esse Quam Videri

Yes, in this respect, your position and that of the Indirect Realist is the same, in that phenomenal experience is non-conceptual and therefore cannot represent the world at all.

The Indirect Realist avoids external world scepticism by deriving concepts based on consistencies in these phenomenal experiences. Using these concepts, which can represent, the Indirect Realist can then rationally employ "inference to the best explanation” to draw conclusions about an external world causing these phenomenal experiences.