The step you keep taking is from: "the object perceived must in fact be causally responsible if perception is veridical" to "the perceiver must know or believe that the object caused the perception." That step simply does not follow. — Esse Quam Videri

Step 1 - If I perceive the Sun, and my perception is veridical, there must be a Sun in the world
Step 2 - If a DR perceives a Sun, they know that the Sun caused their perception. If an IR perceives a Sun, they don’t know what caused their perception.
As far as I can see, both 1 and 2 are correct.
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Direct Realism requires causal dependence as a metaphysical condition of perception, not causal knowledge as part of perceptual content. — Esse Quam Videri

Both the DR and IR require causal dependence as a metaphysical condition of perception, because they both believe in Realism.
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This is precisely why illusions are possible: one can perceive as of the Sun without knowing what actually caused the perception. So the illusion argument does not show that DR is committed to knowing causal initiation; it presupposes the opposite. — Esse Quam Videri

On the one hand, when the DR perceives a Sun they know that the Sun caused their perception, which is why they are DR’s. On the other hand, the DR accepts that when they perceive a Sun it may be an illusion. DR seems to be a contradictory position to hold.

It is the IR who accepts that what we perceive may not be veridical.
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On inference: I’m not denying that we can infer from regularities in perception. I’m pointing out that inference to the best explanation presupposes some non-inferential constraint by the world in order for explanations to be better or worse at all. Otherwise, the regularities you cite are equally compatible with indefinitely many hypotheses. The regress is not inference-from-inference, but inference with no account of how perceptual appearances are answerable to the world in the first place. — Esse Quam Videri

I regularly perceive a yellow circle. I can infer infinite possible causes, such as an illusion, hallucination, God in the world, Sun in the world, Moon in the world, mind in a vat, etc.

Why choose one possibility rather than another. What constrains one’s choice?

The constraint comes from other perceptions, such that there is a logical coherence in all my perceptions. Perceptual appearances are answerable to the establishment of a coherent set of perceptions from which a logical world can be inferred using reason to the best explanation.

There is no conclusive objective details of proof or demonstration how physical brain relates to the mind yet. — Corvus

:100:

Light does not appear to you. It enters your eyes and, after some other intermediary activity mental images appear to you. Light stops being light at your eyes. Your brain literally constructs images from the data which your eyes derived from that light, as electrical signals, within your brain. This is why you can get after images, because your brain is still constructing an image due to an excess of light enter the eye and distorting the objects its reflected off. This should be sufficient to at least give you pause. You cannot see an object witout light - light is a medium which is not in or of the objects it reflects off of. There is no possible room to call mental images direct, unless you do the thing of saying "direct representations" which is a misnomer because representation already infers intermediacy.

If humans don’t see light why do we have lightbulbs?

It’s interesting stuff, sure, but it is not sufficient to give me pause because humans have looked in the brain and have seen no images or anything that constructs images.

Moreover, I do not rely on first person accounts to explain mental phenomena, including my own, because that view is inherently limited. If I’m having hallucinations I’m going to get a second opinion. I’m going to get someone to look in there and trust that he has a better grasp than I do.

While you and Michael claim there is the proverbial veil blocking us from direct access to the world, I say that the veil blocks your access to the goings on of your own brain. I say this for the simple reason that the senses point outward. I cannot even see my own ears, let alone what is occurring inside my head. All I can do with such a limited view of “mental phenomena” is to try to make sense of the fleeting feelings given to the closest sense receptors, and those are often unreliable. Again, this is why we have sophisticated imaging contraptions, specialized doctors, and brains in jars: so that we can better understand what is occurring in there.

So I believe you guys are the naive realists, not only for claiming there exists things in the head that cannot be proven to exist, but because you believe you have a superior epistemological grasp of what is occurring behind your senses rather than in front of them.

My objection is to your objection to my claim that the words "red", "pain", "cold", etc. refer to the phenomenal character of first-person experiences. — Michael

That's not my argument. My argument is that I don't know anything about your beetle and I don't speak about it. It's entirely agnositc as it relates to your first person experience and what it might be.

You can speak about it, but you might not understand it. — Michael

Well, of course. I might not understand anything you say because it's as impossible to know what your beetle looks like or for you to know what mines does. Do I know what you mean when you say "red"? Sure, based upon the way it is used. Do I have any ability to see your red and compare it to mine? Of course not.

But this is beside the main point I'm making here. If we can all communicate as well as we do without reference to the phenomenal state, it drops out as an irrelevant epiphenomenon of meaning. That is, if we say that meaning is fully derivable by usage and public correction and I agree with you that for each and every usage there is a private referent that also fully provides meaning for that term, then what follows is that we can derive the meaning from either of the two independently. Since that follows, and the private referent is a hidden and inaccessible entity that cannot be shown or known to the person receiving the communication, then if we wish to derive meaning, we must turn to usage.

P1. Headaches are private sensations
P2. The word "headaches" refers to headaches
C1. Therefore, the word "headaches" refers to private sensations

I don't know if you're trying to argue that P1 and/or P2 is false, or that C1 doesn't follow, but nothing you've said has convinced me that this argument isn't sound.

Phenomenal states just aren't irrelevant. There is more to colours and pain than the public use of the words "colours" and "pain"; there is also the phenomenal states that the blind and those with CIPA don't have and that we do.

You probably have quite a bit of confidence in your ability to read routine motivations without any episodes of language use.

On reflection, you may be skeptical about this reading ability, but "use" or successful social interactions don't really confirm anything for you. You're doing some special pleading in that you respect beetle skepticism, but ignore the larger looming skepticism that threatens everything you think you know.

In other words, how do you know what other people feel? The same way you know anything.

I do get the impression you both feel that scientific discoveries demand that we should accept the metaphysical picture that indirect realism seems to draw. However, I have attempted to show science gives little to no support to such a philosophical theory. As indirect realism retreats into private first person experiences, science needs to find consensus in the public realm. Much of the foundation of science starts with basic human agreement. We start to learn color concepts not by private introspection, but by being presented with color standards, community reinforcement of color language, and general consistency in color judgement. If we don't have this general harmony, the whole language game of colors may have never gotten off the ground for us to create alternate descriptions of color like the use of wavelengths. Additionally, I attempted to present a picture of science where we may want to use the word "direct" if we view perception as a biological processes like hydration, digestion, and respiration. If hydration directly processes H2O, why can't we say perception directly processes light?

I like to present one more argument that science does not support indirect realism. In fact it actually ignores it all of the time. Science does not treat observables as private introspection mental phenomena but as public, stable, and law governed. Science manipulates and predicts these observables and does not consider them mental accidents. Hallucinations do not come into play if scientific outcomes result in variance. Others considerations are given weight like, measurement error, experimental set-up, statistics, and theoretical framing. Mental phenomena, like hallucinations, serve no global explanatory role and methodologically irrelevant. You might say, we should keep "realism" and drop "direct/indirect" and understand we are causally embedded biological organisms whose process of perception supports interventions, coordinations, and manipulations of our environment.

To repeat an earlier quote from A Problem with Color:

One of the major problems with color has to do with fitting what we seem to know about colors into what science (not only physics but the science of color vision) tells us about physical bodies and their qualities. It is this problem that historically has led the major physicists who have thought about color, to hold the view that physical objects do not actually have the colors we ordinarily and naturally take objects to possess. Oceans and skies are not blue in the way that we naively think, nor are apples red (nor green). Colors of that kind, it is believed, have no place in the physical account of the world that has developed from the sixteenth century to this century.

Not only does the scientific mainstream tradition conflict with the common-sense understanding of color in this way, but as well, the scientific tradition contains a very counter-intuitive conception of color. There is, to illustrate, the celebrated remark by David Hume:

"Sounds, colors, heat and cold, according to modern philosophy are not qualities in objects, but perceptions in the mind." (Hume 1738: Bk III, part I, Sect. 1 [1911: 177]; Bk I, IV, IV [1911: 216])

Physicists who have subscribed to this doctrine include the luminaries: Galileo, Boyle, Descartes, Newton, Thomas Young, Maxwell and Hermann von Helmholtz. Maxwell, for example, wrote:

"It seems almost a truism to say that color is a sensation; and yet Young, by honestly recognizing this elementary truth, established the first consistent theory of color." (Maxwell 1871: 13 [1970: 75])

This combination of eliminativism—the view that physical objects do not have colors, at least in a crucial sense—and subjectivism—the view that color is a subjective quality—is not merely of historical interest. It is held by many contemporary experts and authorities on color, e.g., Zeki 1983, Land 1983, and Kuehni 1997. Palmer, a leading psychologist and cognitive scientist, writes:

"People universally believe that objects look colored because they are colored, just as we experience them. The sky looks blue because it is blue, grass looks green because it is green, and blood looks red because it is red. As surprising as it may seem, these beliefs are fundamentally mistaken. Neither objects nor lights are actually “colored” in anything like the way we experience them. Rather, color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. The colors we see are based on physical properties of objects and lights that cause us to see them as colored, to be sure, but these physical properties are different in important ways from the colors we perceive." (Palmer 1999: 95)

Cheers.

ou appear to accept that the sensations occur but then for some reason think that they have nothing to do with the meaning of the words we use. — Michael

(1) as sensation reports or (2) as world-directed predicates. — Esse Quam Videri

We differentiate quite simply between the bath being hot and it's feeling hot.

We might add that it sometimes makes sense to say that the water is cold but feels hot - when you have been out in the snow, perhaps, or due to erythromelalgia.

If @Michael's view were accepted, such that "hot" refers only to the sensation and not the water temperate, then this would not be possible. For him, if the water feels hot, "hot" refers to a sensation, and not to a fact about the water. So for him if the water feels cold, it is cold. And this is so regardless of wha the thermometer shows.

So he could have water at 5℃ and it still be true that the water is hot, because "hot" refers to a sensation, not a temperature.

Now this might even be consistent, at least with itself, and might explain why Michael is so enamoured with this view. Except that it is not how we do talk.

I don’t deny that sensations occur — Esse Quam Videri

Nor do I. The point here is that "the water is hot" is about the water, not about how the water feels. The re is a difference between "The water is hot" and "The water feels hot" this cannot be made in your account, Michael.

The example neatly shows a natural language differentiation between two locations for the Markov Blanket. The language track two loci, world-side features and subject-side sensations, effortlessly.

So here

Both John and Jane agree on the temperature. Is 37°C hot or cold? What do the words "hot" and "cold" mean in either case? I think it quite obvious that they refer to the different sensations that 37°C water causes John and Jane to feel. — Michael

Michael asks if 37°C is hot or cold. Now if being hot or cold is exactly a sensation, this would be the same as asking "Does 37°C feel hot or does it feel cold?" But it isn't. Therefore the presumption that "hot" refers to a sensation is mistaken.

Yep.

Yep. @Michael doesn't seperate the epistemically and causal chains.

The word "headache" refers to the sensation we tend to feel after a heavy night of drinking, the word "cold" refers to the sensation we tend to feel in low temperatures, the word "hot" refers to the sensation we tend to feel in high temperatures, and the word "pain" refers to the sensation we tend to feel if stabbed. — Michael

Again, "headache" is not like "hot". John and Jane can disagree as to the water being hot, but not as to John having a headache: We get John saying "the water is hot" and Jane saying "no it isn't", but not John saying "I have a headache" and Jane saying "no I don't".

Your analogy misfires.

There is more to the meaning of these words than just their "public use". There is also the sensations they refer to. — Michael

This is an interesting move, in that you here allow for a public use as well as reference to sensations. Your previous accounts have insisted that words such as "hot" refer to the sensation alone. That's progress. No one here, so far as I can see, is saying that we do not have sensations. They are pointing out that we can refer to how things are, as well as how things feel: that there is a difference between "The water is hot" and "The water feels hot"; between "The ship looks red" and "The ship is red"; between "That is my wife's voice" and "That sounds like my wife's voice". And that we can talk about how things are as well as about how things appear to us. Indirect realism has to do work in order to explain this, usually by saying we make an inference from the sensation to the fact; but this is nonsense. We certainly do not actively, consciously infer from "That feels hot" to "That is hot", or from "That ship looks red" to "That ship is red". And if it is supposed that the inference is made somewhere beneath consciousness, then we must have a discussion about why we should call it an inference at all. What we feel is the water, what we see is the ship.

So you've moved slightly. Now you must either retreat further and accept world-directed predicates, or
double down and deny ordinary disagreement, authority, and usage.

"People universally believe that objects look colored because they are colored, just as we experience them. The sky looks blue because it is blue, grass looks green because it is green, and blood looks red because it is red. As surprising as it may seem, these beliefs are fundamentally mistaken. Neither objects nor lights are actually “colored” in anything like the way we experience them. Rather, color is a psychological property of our visual experiences when we look at objects and lights, not a physical property of those objects or lights. The colors we see are based on physical properties of objects and lights that cause us to see them as colored, to be sure, but these physical properties are different in important ways from the colors we perceive." (Palmer 1999: 95) — Michael

You keep bringing this quote up. It shows pretty clearly the confusion of the epistemic and the causal accounts that you rely on, ignoring the difference between "It looks red" to "It is red", treating these as if all we ever have is "It looks red" and never "It is red". This is the account given by the "indirect realist", who then supposes that anyone who disagrees with them must think that if it looks red then it is red, and calls these folk "direct realists".

The rest of us see the muddle, and recognise the difference between "It looks red" and "It is red".

There is a great critique by Norman Malcolm of the thought experiment that there could be Martians who have our "sensation of heat" when exposed to cold and our 'sensation of cold' when exposed to heat. He said,

"What sort of behavior on the part of the Martian would justify us attributing to them "sensation of heat and cold' in this sense? Are we to imagine that when they enter a hot room or stand near a hot fire they begin to massage themselves and to put on more clothing? But this would be unsuitable behavior for the Martians. Massaging one's body and donning more clothing is warming because it increases the heat of the body. If the Martians adopted those measure they would show themselves to sensitive to heat as heat, which they are not supposed to be. This description of the Martians would seem to be contradictory. On the one hand, they are not sensitive to heat; on the other hand, they are sensitive to and grateful for the increase of bodily heat produced by putting on more clothing."

He goes on to show the incoherence of the opposite view as well. The ultimate conclusion Malcolm draws is to show the conceptual connection between a sensation and the natural expression of that sensation in behavior. To sever this connection is to cease to employ the concept of sensation.

Norman Malcolm — Richard B

Another escape from Oxbridge natural language philosophy. Yes, good stuff. The formalisation of this came with Davidson, and then the partial dissolution. Davidson disarmed the metaphysics, but the itch remains.

A thermometer is put into water. When the thermometer reads 10deg C, the water is given the public name “cold”. When the thermometer reads 30deg C, the water is given the public name “hot”.

John sits in water, feels a private sensation, sees the thermometer read 30deg C, and says “I feel hot”. Jane sits in water, feels a private sensation, sees the thermometer read 30deg C, and says “I feel hot”.

It may well be that John feels the same private sensation when sitting in “hot” water that Jane feels when sitting in “cold” water.

No one can know, because no one can know another person’s private sensations.

The Indirect Realist accepts that it may well be that John feels the same private sensation when sitting in “hot” water that Jane feels when sitting in “cold” water.

The Direct Realist has the untenable position that i) John cannot possibly feel the same private sensation when sitting in “hot” water that Jane feels when sitting in “cold” water and ii) John must feel the same private sensation when sitting in “hot” water that Jane feels when sitting in “hot” water.

The word “hot” refers to both i) John’s private sensation and ii) the temperature of the water. The word “hot” does not mean that i) John’s private sensation and ii) the temperature of the water are the same thing.

Again, "headache" is not like "hot". — Banno

If just one word refers to private sensations then this argument that you and Hanover keep pushing that meaning is just public use, that private sensations must drop out of consideration because we can't know each other's experiences, etc. is shown to fail. Clearly you understand what the word "headache" means even though it does refer to a private sensation. You might want to argue that colours aren't like headaches, e.g. take the naive colour realist approach, but no deference to Austin or Wittgenstein (or language) suffices to prove this.

John and Jane can disagree as to the water being hot, but not as to John having a headache — Banno

But people do say "stop exaggerating, it doesn't hurt that much". This idea you have that our everyday way of talking to each other and about the world has bearing on phenomenology or perception or physics or metaphysics just doesn't hold up.

If John and Jane both agree on the water's temperature but disagree as to whether this temperature is hot or cold then what is the actual substance of their disagreement? What does it mean for 37°C to be hot or to be cold? What does it mean for an injection to be painful? The common sense and parsimonious answer is that it concerns how such things feel to us, i.e. the types of first person phenomenal experiences they cause. Any "disagreement" stems from the naive (and mistaken) assumption that there's a "right" way for 37°C water or an injection to feel — or it's faux disagreement that ought not be taken literally; they're just describing how the water and the injection feels to them and acknowledging that they feel different to the other.

If just one word refers to private sensations then this argument that you and Hanover keep pushing that meaning is just public use, that private sensations must drop out of consideration because we can't know each other's experiences, etc. is shown to fail. Clearly you understand what the word "headache" means even though it does refer to a private sensation. You might want to argue that colours aren't like headaches, e.g. take the naive colour realist approach, but no deference to Austin or Wittgenstein (or language) suffices to prove this. — Michael

Can you give me an instance where use does not suffice to provide meaning?

What is it?

If just one word refers to private sensations then this argument that you and Hanover keep pushing that meaning is just public use, that private sensations must drop out of consideration because we can't know each other's experiences, etc. is shown to fail. — Michael

's point was to show that the use of the word "headache" is not like the use of the word "hot". The latter is a world-directed predicate, while the second is an avowal of a condition of a subject. The difference is that while John and Jane can disagree over whether the water is hot, Jane can't intelligibly deny that John has a headache, unless she's challenging John's honesty or sincerity.

But even so, the word "headache" is not an example of "reference to private sensation" in the way you want/need it to be. Semantically the word "headache" is bound up with location, duration, causes, remedies, norms of exaggeration, medical correction, etc.

That's not to deny that private sensation can play a causal or evidential role. The headache causes me to say "I have a headache" and it is evidence for me that what I say is true. But it does play a constitutive semantic role. The private sensation is not (and cannot be) the referent of the word "headache" because they (being private) cannot be part of what makes it correct to incorrect to apply the word here and now.

If public use + correction + practice are already sufficient to fix reference, then adding private sensation does no semantic work.

then adding private sensation does no semantic work. — Esse Quam Videri

It does. There are no headaches without the private sensation.

Can you give me an instance where use does not suffice to provide meaning?

What is it? — Hanover

See above.

See above. — Michael

Where am i looking?

There are no headaches without the private sensation. — Michael

No one denied this. The issue isn’t whether sensations are involved; it’s whether private sensations are what words mean or refer to.

Again, if public use + correction + practice are already sufficient to fix reference, then adding private sensation does no semantic work.

There are no headaches without the private sensation. — Michael

I'll repeat what I said to Hanover.

P1. Headaches are private sensations
P2. The word "headaches" refers to headaches
C1. Therefore, the word "headaches" refers to private sensations

I don't know if you're trying to argue that P1 and/or P2 is false, or that C1 doesn't follow, but nothing you've said has convinced me that this argument isn't sound.

But really, all this talk about language is irrelevant to the topic of perception. P1 is sufficient to understand what is meant when we say that things like smells and tastes and colours are private sensations.

There are no headaches without the private sensation. — Michael

Just an obvious category mistake at this point, refusing to distinguish ontological cause from grammatical meaning. That a given X owes its existence to Y doesn't implicate Y as the definition of X.

It's about to rain here, and rain means what rain does, without regard to it being caused by a pressure differential. To say this rain is that does not mean rain means that. To conflate meaning with cause at this point seems to ignore all that has been said.

Headache can mean the pain in one's head even while there is no pain in the head. Headache cannot mean the pain in one's foot if it is used to mean pain in one's head.

The word "rain" refers to the water falling from the clouds, and the word "headache" refers to the sensation I feel having to belabour this very obvious truth.

I'll repeat what I said to Hanover.

P1. Headaches are private sensations
P2. The word "headaches" refers to headaches
C1. Therefore, the word "headaches" refers to private sensations — Michael

Again, where is this word "means' in your proof?

Again, where is this word "means' in your proof? — Hanover

Where have I ever used the word "means"? You keep bringing it up, despite me repeatedly saying that I am only arguing that the word "headache" refers to a private sensation.

The word "rain" refers to the water falling from the clouds, and the word "headache" refers to the sensation I feel having to belabour this very obvious truth. — Michael

Still in a category mistake. You're not talking about meaning.