The point that's being made is . . . — Michael

..and that point arises from the false assumption that there exists something (e.g. sense-data, phenomena etc.) by way of which all things are experienced. It explains away the possibility of things being experienced as they are, and thus it muddles up perception of real things with dreams, illusions, hallucinations etc..

. . you don't know that, because you haven't antecedently figured out that all, or any particular, perception is not an illusion. — The Great Whatever

Look, there is no need to first figure out what a veridical perception should look like; perceptions are not somehow comparable representations from which we'd know whether a current perception isn't an illusion. The real object that you perceive looks as it is, not like something else, and unlike illusions the real object won't suddenly appear or disappear as you move around it etc.. It is not difficult to identify whether something passed for an object of perception is an illusion or a real object that one sees.

Now the question is just about whether you're seeing merely light or the object. — The Great Whatever

Your question makes no sense, because when we see the object we also see the light it reflects, not either light or the object. We can also see emitted light without seeing an object, e.g. a flashlight, that emits it.

the same experience can be one of seeing something or seeing nothing, and you aren't able in principle to distinguish between the two. — The Great Whatever

Hallucinations are hardly as recalcitrant, continuous, and non-detachable as the objects of veridical cases of perception. The existence of sense-data is not disvovered by having experiences, they're blindly assumed in the representationalist doctrine according to which we never see objects and states of affairs directly.

None of these rhetorical moves are ever going to work, because they all have the same structure — The Great Whatever

They work when you let go of representational perception. Also direct realists account for dreams, imagination, illusions, hallucinations etc

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How would you describe yourself? — saw038

For what reason?

you still have to come up with an explanation for hallucination, claiming that it's a real perception not of sense-data, but of a misleading ocular phenomenon, or something like that. But then we just have the same problem, rewritten without sense data: how do we know that all of our perceptions are not just of these misleading ocular phenomena and not of what we think they are? — The Great Whatever

You have the same problem because ocular phenomena are hardly less representational than sense-data.

It is not an ocular phenomena that we see in the case of an illusion but the real behaviour of light, as in refraction, or real shaded shapes, as in Mach-bands. In Mach-bands we see grey shapes as they are, but exaggerate the contrasts between the greys. The exaggeration is a use of the greys that we see, a way to organize them, but which is incorrectly passed for something present in our eyes or minds, yet absent somehow. But absent things are not present, neither in your eyes, nor inside your head. A memory of something absent does not possess parts of what it is a memory of.

In the case of hallucinations nothing is seen. The hallucinatory experience is not an impression evoked by, nor referring to, some synaptic screw-up; it is the screw-up that is experienced directly. Like the mind's organization of Mach-bands the mind attempts to make sense of the hallucinatory mess caused by drugs, disease, fatigue etc., by evoking "perceived" things despite their absence, hence 'hallucination'. It is simply incorrect to pass hallucinations for perceptions.

how do I know whether everything I'm seeing isn't what I think it is — The Great Whatever

Obviously not by continuing to assume representational perception; basically your question and problem arises from that asumption, i.e. that you only see your own impressions, sense-data or the like, and never the objects directly.

I don't make that assumption.

nothing about having a certain visual impression implies the metaphysical conclusion that something external is causing this impression). — The Great Whatever

Whence the assumption that it would be an impression? See, you continuously assume representational perception without noticing it .

To be clear, the argument from illusion concludes the existence of sense-data. But in its premise it is assumed that the appearance of the illusion somehow exists but not its object. Hence the conclusion that there must exist sense-data. But what appears in the case of an optical illusion is not the appearance of an absent object but some real effect of optics, such as refraction, or some real bundle of coloured shapes etc.. Those are examples of things we truly see in the case of optical illusions, but which we tend to mistake for something else. Without seeing real things there would be no illusions.

Nothing in the child's whole environment would be real though, of course, entirely real to the child. — Barry Etheridge

Only under your false assumption that the child would never see the real environment. In the arguments from illusion and hallucination representational perception is assumed, which makes them bad when used against arguments in which representational perception is not assumed.

In any event Ryle's argument need not apply at all in the case of the dreamworld for it is not necessary to even posit that it is a counterfeit of anything. — Barry Etheridge

Sure, but that was not asked in this thread. All can't be a dream, for then there would be nothing left to dream of.

In the argument from illusion it is (incorrectly) assumed that we'd never see reality as it is, which basically explains away the possibility to distinguish an illusion from the veridical case of perception, and then skepticism is off and running. But no such assumption is made in Ryle's counterfeit argument, and you don't get to sneak in unwarranted assumptions.

. . life . . sure feels real! But, the problem for me is so do my dreams. — saw038

The life that feels real to you feels real because it is the reality of life that you feel. The dream that feels real to you feels real because it is the reality of your memories and empathy that you feel, which makes it different.

It's a logical fact that all of something cannot be counterfeit

. . you cannot state as incontrovertible fact that it is any more than you can prove that we're not all just a figment of God's imagination. — Barry Etheridge

But as Gilbert Ryle once argued: all of something can't be counterfeit, for then there is nothing left it could be counterfeit of. Seems fairly incontrovertible to me.

Dreams are but experiences of representations of life (memories, beliefs, pictures, descriptions). Life, however, is not a representation: e.g. it is not detachable by waking up, it is here and now, and flows continuously.

What do you think this states about the human mind and our ability to comprehend the world? — saw038

We've improved our ability to comprehend the world. I recall Gödel was a platonist.

. . it logically follows because we can imagine going to sleep and never waking up (at least, crudely); therefore, we should be able to imagine the inverse; that is, waking up without ever having gone to sleep. — saw038

No, there is no such thing to imagine, because the ability to identify what something is like is acquired when one is awake. If you have never been awake before, then there can be no such thing to imagine as waking up without ever having gone to sleep. Also "crudely" it would be a fictional story of what something was like but which couldn't have been like anything.

If we see things directly there are no illusions. — Barry Etheridge

Also in the case of illusions we see things directly: e.g. optical effects such as refraction, or two lines whose ends make their lengths appear different and so on. Without seeing these things directly there would be no illusion.

The only reason that optical illusions work is that the brain overrides the evidence of our eyes to impose its own expectations upon the image. — Barry Etheridge

In optical illusions it is always the case that something is seen, hence 'optical'. Yet you omit optics and instead pass a figment of brain and expectations for vision. You're on your own.

One photon: http://www.latimes.com/science/sciencenow/la-sci-sn-human-eye-photon-20160719-snap-story.html

Except that is exactly what happens in one of the most famous optical illusions. We simply do not see an exact map of the photons received at the retina. . . . — Barry Etheridge

Don't you get it yet? There is no need for an exact map when we see objects directly. From illusions it does not follow that all we see would be illusions.

We do of course know that the visual cortex can and does operate without photons because we have visual dreams and hallucinations. — Barry Etheridge

Without photons your visual cortex "operates" only hallucinations, in which nothing is seen. That's why they are called 'hallucinations'.

. .what we see is a construct bearing little or no resemblance to what is actually sending photons toward us. — Barry Etheridge

And how could you see that it has a different construction than what we actually see? Divine vision? Or is it somehow implied by the trivial fact that we sometimes mistake the things we see for something else?

I think it is obviously true that what causes an object to appear rectangular is its real construction. The brain does not fabricate a rectangular picture of an object explained away as invisible.

What does fine art do for you? — Bitter Crank

It provides things worthy of respect.

Which part of receptor (eye) in combination with signal interpreter (in this case the cerebrum) did I fail to clarify? — Barry Etheridge

The important part: their cause, which you explicitly omit:

"You don't see light. You respond to an electrical signal transmitted from a receptor in your eye which obviously isn't light at all." — Barry Etheridge

(..and obviously no-one claimed that light would somehow occur inside the nervous system.)

One photon is sufficient to cause a detectable signal and response, but without photons you'd see nothing. Instead you assume a "signal interpreter" fabricating mental "movies" with lights etc., of a world in the dark, which is as absurd as solipsism.

With what organ do you see the alleged things inside your head, hm?

Why would experiences "need interpretation"? Seeing light is a 'basic action' by way of which anything visible is seen, but one does not need to interpret, nor see something else, in order to see light.

Seeing light "as it really is" is to see light without an assumed intermediate representation.

Sure, why? And no, they didn't experience some false behaviour of neutrinos, it was their interpretation which was false due to a screwed up cable or the like. The possibility to mess with the conditions of observation to mislead the observer is no reason to believe that all observation would be unreliable. An optical illusion wouldn't be possible without seeing light as it really is, refraction as it really is, etc.

It is trivially true that beliefs or expectations could be wrong. Likewise, some beliefs or expectations could be right. Experiences, however, are facts. There is no good reason to be unsure of whether this web page exists as one's eyes are interacting with it.

Ok, but are you sure of fallibilism? Granted that statements and beliefs can be wrong as they are representational. But experience is presentational. What you see, hear etc under such and such conditions couldn't be anything but what you see, hear etc (despite the possibility to interpret it, i.e. form beliefs about it in various ways).

What's an example of an alternative? The objective world is not manufactured by experiencing it.

Again, to also revolve around other things wont make 'The earth revolves around the sun' false

You wish. But to also revolve around other things wont make 'The earth revolves around the sun' false.

Objective truth means that a statement has the property of referring to something which is the case independently of our beliefs or statements.

For example, "the earth revolves around the sun" is true by referring to what is the case, and objective by being true independently of whether anyone says or believes it.

By asking "what is the nature of truth" we might want to investigate and discuss conditions which satisfy the possibility that a statement is true. It is pretty much the nature of philosophy to ask questions about the nature of things.

To see "..the real mind-independent apple as it is..." means to see it directly. The apple of your mind-dependent experience is the mind-independent apple that you experience. — jkop

This is circular. I asked what it means to see a thing directly and you said it's to see a mind-independent thing as it is. I asked you what it means to see a mind-independent thing as it is and you say it's to see a thing directly. So, currently, the very notion of seeing a thing directly – of seeing a mind-independent thing as it is – is vacuous. — Michael

There's "currently" a seeming circularity in your refereeing of my replies, but not in my replies.

it's largely just a debate about how we should use words? — Hoo

If there is ambiguity in our talk we should debate how we should use the words. Or else we'll just end up talking past each other, using words in different senses without realising it.

All perception is veridical, unlike hallucinations, in which nothing is perceived, only experienced. It would be unnecessarily ambiguous to speak of 'non-veridical' cases of visual perception, for example, when there is no vision, only experience of vision. In veridical cases something is both seen and experienced.

Also optical illusions are veridical in the sense that something is both seen and experienced, such as light, reflections, refractions, atmospheric effects and so on. A brain in a vat would never see, for example, the optical illusion in a photo-realistic picture, because seeing the illusion requires seeing something which is really there, such as real light, real patches of paint etc..

To see "..the real mind-independent apple as it is..." means to see it directly. The apple of your mind-dependent experience is the mind-independent apple that you experience.

If it's orange but it appears to you as red then you're seeing it wrong. — Michael

Seeing it directly means that it couldn't appear red when it is orange. Only appearance as representation could be wrong, but naive realism denies that perception would be representational. So, evidently, you have yet to understand naive realism.

The "perception" possessed by a brain in a vat would only be representational, i.e. a simulation.

And its theory on perception is that, in the veridical case, the properties we perceive an object to have are properties that the object has even when we don't see them. — Michael

Its theory of perception is obviously not a theory about the properties we perceive an object to have but about the nature of perception: that it is direct.

For example, that when we see a red apple we're not seeing an intermediate representation of an apple inside our minds but the real mind-independent apple as it is. This does not mean that the apple would somehow have to appear red also when we don't see it, in the dark, for instance. If this is what you believe of realism, then you simply don't understand realism.

What is mind-dependent is perception: e.g. seeing the apple is to be consciously aware of its presence in your visual field, for instance, and its colour. It's possession of the colour, however, only means that it will reappear under the same or similar conditions which satisfy the possibility to see colours.

on whether or not the apple being red is perception-independent. — Michael

Category error. Being is not seeing. Apples are seen as red. Naive realism is a theory of perception, recall, not ontology.

That's a false dichotomy, for neither realism nor naive realism reject perception or its dependence to there being something with which we can perceive the world (e.g. a mind and certain background capacities). Realism (concerning ontology) states that what exists is not dependent on the existence of a mind. Naive realism (regarding perception) states that we perceive objects and states of affairs directly, i.e. not via some copy or picture conformed inside our minds. "Meanings just ain't in the head." with regards to Putnam. But one might add that without the head there ain't any perception.

He started as a naive realist, moved on to internal realism, and then ended up defending natural realism. — Michael

..or in his own words: How to Be a Sophisticated "Naïve Realist" (2011)

That's a selective truth when referring to the book, but misleading when referring to Putnam's stance on realism. As I said, he ended up defending naive realism.