Your visible/invisible distinction seems irrelevant, at least for the one imagining the cat.
— Luke

A cartoonist who imagines a fictional cat might find it relevant to also see visible cats. — jkop

However, there's a feeling in what it's like to see the cat, which is comparable with a feeling of what it's like to see the cat-picture. There's also a feeling in what it's like to imagine a cat. You can compare your feelings (via memories), and judge resemblances between them. — jkop

No, I just feel them. What I feel is my physiological state, in which hormones and neurotransmitters etc are constitutive for having it. — jkop

But feelings are invisible, you can't compare a visible cat nor graphic image with the feeling of imagining what they look like. You can, however, compare things of the same type, such as two visible cats, two visible images, or two invisible mental states by how they feel when you have them. — jkop

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

Well, for example, alcohol can affect my mental state so that I feel tipsy, a blurry kind of feeling, which in turn resembles the blurry feeling of seeing blurry or expressive pictures, or hearing blurry sounds, etc. There is something genuinely blurry about feeling tipsy, or in what it's like to see blurry pictures etc. — jkop

Imagining a cat may resemble seeing a cat (or cat-like doodle) since the levels of hormones and neurotransmitters that evoke the mental states in both cases can be similar or the same. Hence their resemblance. — jkop

A "mental image" couldn't even resemble visible objects such as cats or images — jkop

What's mental is the intent to find out what the cat might look like, which may feel like seeing, since it can be satisfied by one's ability to use memories and beliefs about cats. It can also be satisfied by doodling with a pencil on paper until the visible shapes of a drawn cat satisfy what you had in mind. But what you had in mind was never an image, only a hunch, a feeling evoked by the intent etc. — jkop

We can understand the meaning of a word, say the German word for "village" and have not the first clue how to use it in a sentence. — Count Timothy von Icarus

Yet we can also know how to use words without knowing what they mean. For example, plenty of people use "e.g." "QED," "i.e.," or "amen," correctly without knowing what they mean. — Count Timothy von Icarus

Is there a difference between knowing someone's pain and knowing that someone is in pain? — Michael

We cannot know other minds because our relation to others is not knowledge, but how we treat them, our “attitude” in relation to them, in its sense of: position “towards”. I treat you as if you have a soul. — Antony Nickles

As with others’ souls (p. 178) or the pain causing another to writhe in front of us (p. 235), we do not know it, because that is not how knowledge works. We respond to them (or ignore them). That is how humanity and pain are treated, the way in which they matter to us, their grammar. — Antony Nickles

There are two different senses of “know” here at p. (246), one being: with certainty, the other being knowing as acknowledging, recognizing. The part of the sentence you are quoting is the second kind. “I’m in pain.” “I know” or “He’s in pain!” “I know, but he’s so dramatic, he’ll be fine.” — Antony Nickles

Another’s pain is not known, it is responded to — Antony Nickles

I walked into that. But at the start of the sentence he says “If we are using the word ‘to know’ as it is normally used…” — Antony Nickles

As with others’ souls (p. 178) or the pain causing another to writhe in front of us (p. 235), we do not know it, because that is not how knowledge works. We respond to them (or ignore them). — Antony Nickles

Yes, hence the epistemological problem of perception. — Michael

Naive realists claim that sensory perception does provide us with direct knowledge of distal objects because distal objects are literal constituents of conscious experience, and so we are acquainted with distal objects.

Indirect realists claim that sensory perception does not provide us with direct knowledge of distal objects because distal objects are not literal constituents of conscious experience, and so we are only acquainted with mental phenomena. — Michael

It's only equivocation if they start from the premise that we are acquainted with mental phenomena and then conclude that our eyes respond to light reflected by mental phenomena, but they never draw this conclusion. This is the strawman conclusion that you and others are fabricating. — Michael

What indirect realists mean by "perception of some other entity" isn't what you mean by "perception of some other entity". You're equivocating. — Michael

Except by this you mean "our eyes respond to light reflected by sense data" which isn't what indirect realists believe. — Michael

So what is it that indirect realists believe that you do not? — Michael

As I've stated several times now, it is over part (2) of Fish's definition:
— Luke

Except according to what you mean by "perceive some other entity, such as sense-data", (2) is something that indirect realists accept. — Michael

You think that by "we perceive mental phenomena" the indirect realist means "our eyes respond to light reflected by mental phenomena". They don't. — Michael

where is it that non-naive direct realism and indirect realism disagree? — Michael

(2) that our visual perception of [...] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part);

Naive realists claim that distal objects and their properties are literal constituents of conscious experience and that as such we are acquainted with distal objects and their properties, and so our knowledge of them is direct and there is no epistemological problem of perception. The external world just is as it appears. They call this "direct perception of distal objects". — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part).

Indirect realists don't believe or claim that our eyes respond to light reflected by mental phenomena and that our ears respond to sound emitted by mental phenomena, so you clearly misunderstand indirect realism and are arguing against a strawman. — Michael

What do you think "perceive mental phenomena" means? Do you think it means that my eyes respond to light reflected by mental phenomena? Do you think it means that my ears respond to sound emitted by mental phenomena? — Michael

I think you're reading something into the meaning of "perceive mental phenomena" that just isn't there. Indirect realists probably aren't saying what you think they're saying when they say that we perceive mental phenomena. Acquaintance with mental phenomena is the appropriate interpretation. — Michael

This is how to interpret the meaning of "feel" in "I feel pain" and the meaning of "hear" in "the schizophrenic hears voice" and the meaning of "see" in "I see colours". — Michael

This sense of acquaintance with mental phenomena occurs also in veridical perception, and this is all that is meant when the indirect realist says that awareness of distal objects is mediated by awareness of mental phenomena. — Michael

• How do we perceive the external world?
• What is the relationship between our perceptions and the external objects themselves?
• Are our perceptual experiences direct or mediated?

2.The act of processing visual data: To perceive --> causes
3. Having the resulting conscious experience: To see. — AmadeusD

Sense data just is the unmediated empirical affect the object has, that data, that affect, conditioned by something very different, is the subsequent mediated representation of the perceived object. — Mww

To mediate is to arbitrate or condition; that which is a perception cannot arbitrate or be arbitrated by, another perception. Perception mediated by perception is improper and confusing;
Sense data just is the unmediated empirical affect the object has, that data, that affect, conditioned by something very different, is the subsequent mediated representation of the perceived object. This is indirect realism. — Mww

(2) that our visual perception of […] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part) — Michael

Then where is the mediation of our perception of visual objects by the perception of some other entities such as sense-data?
— Luke

We feel pain – a mental phenomenon – and it is in feeling this pain that we feel the fire. We taste a sweet taste – a mental phenomenon – and it is in tasting this sweet taste that we taste the sugar. We see shapes and colours – mental phenomena – and it is in seeing these shapes and colours that we see the cow. — Michael

You misinterpret what "perceive mental phenomena" means. I feel pain, and pain is a mental phenomenon. The schizophrenic hears voices, and these voices are a mental phenomenon. I see colours, and colours are a mental phenomenon. This is all that is meant. — Michael

And this is where you're reading something into the grammar that just isn't there. — Michael

The existence of something like a mental representation is what it means for our perception of distal objects to be mediated. — Michael

I addressed this before when I asked you to explain the difference between "seeing" a mental representation and "having" a mental representation. You were unable to do so. And that is precisely because there is no difference. — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part). In this, the theory contrasted with theories such as scientific direct realism (which rejected (3)), indirect realism (which rejected (2) and (3)), and phenomenalism, which rejected (1). Today, however, most philosophical theories of visual perception would endorse at least claims (1) and (2), and many would also endorse (3). In this setting, “naïve realism” has taken on a more precise use. As understood today, the naïve realist claims that, when we successfully see a tomato, that tomato is literally a constituent of that experience, such that an experience of that fundamental kind could not have occurred in the absence of that object. As naïve realism, thus understood, sees perception as fundamentally involving a relation between subjects and their environments, the position is also sometimes known as “relationalism” in the contemporary literature. Typically, today’s naïve realist will also claim that the conscious “phenomenal” character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense. On such a view, the redness that I am aware of when I look at a ripe tomato is a matter of my experience acquainting me with the tomato’s color: the redness that I am aware of in this experience just is the redness of the tomato. As such a view appears to commit its proponent to a version of claim (3) above—that for one to see an object to have a feature, the object must actually have that feature—the inheritance of the name “naïve” realism seems appropriate. As for whether there can be naïve realist theories of senses other than vision, this is an issue that awaits a more detailed exploration.

The key parts are in bold.

Specifically, I think that "our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data" means "the conscious 'phenomenal' character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense." — Michael

...our visual perception of [...] material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part)

...the conscious “phenomenal” character of that experience is shaped by the objects of perception and their features, where this is understood in a constitutive, rather than merely a causal, sense. — Michael

Naïve realism is a theory in the philosophy of perception: primarily, the philosophy of vision. Historically, the term was used to name a variant of “direct realism,” which claimed (1) that everyday material objects, such as caterpillars and cadillacs, have mind-independent existence (the “realism” part); (2) that our visual perception of these material objects is not mediated by the perception of some other entities, such as sense-data (the “direct” part); and (3) these objects possess all the features that we perceive them to have (the “naïve” part). In this, the theory contrasted with theories such as scientific direct realism (which rejected (3)), indirect realism (which rejected (2) and (3)), and phenomenalism, which rejected (1). Today, however, most philosophical theories of visual perception would endorse at least claims (1) and (2), and many would also endorse (3). In this setting, “naïve realism” has taken on a more precise use.

To clarify, when you say that, according to naive realism, perceptions and perceived distal objects have the same physical constituents, do you take this to mean that perceptions and the perceived distal objects are identical?
— Luke

You'll have to ask naive realists for specifics of what they mean — Michael

This is the very point I am making. Non-naive direct realism is indirect realism given that they both accept that distal objects and their properties are not constituents of experience — Michael

I can only quote what they say — Michael

which is that the relation between conscious experience and distal objects is more than just causal and is non-representational, using the term "constituent", which means "being a part". — Michael

Indirect realists don't argue that percepts exist, that distal objects and their properties are not constituents of these percepts, and that perception is indirect, as if this latter claim is distinct from the other two. Rather, by "perception is indirect" they just mean that percepts exist and that distal objects and their properties are not constituents of these percepts – and the science of perception supports this. — Michael

What is the physical/physiological difference between mental representations mediating perceptions of real objects and not mediating perceptions of real objects? — Michael

What is the physical/physiological difference between mental representations existing and not being mediations and mental representations existing and being mediations? — Michael

This distinction you're trying to make just doesn't seem to make any sense.

The indirect realist claims that something like mental representations exist, that distal objects and their properties are not constituents of these mental representations, and that we have direct knowledge only of these mental representations. — Michael

I don’t know what you mean by “direct knowledge”. The relevant question is whether or not we have direct perceptions. — Luke

If you want to make the same claim but call it "direct realism" then you're welcome to, but as it stands there is no meaningful difference between your direct realism and my indirect realism. — Michael

You can call it a merely grammatical dispute if you like, but then you must be in agreement with me that our perceptions are mental representations, that our perceptions of the world do not require any mediation, and that we can have direct perceptions of the world.

But I don’t see how this is consistent with the indirect realist position that our perceptions are directly of mental representations and only indirectly of the world; that is, that our perceptions of the world are mediated by mental representations. — Luke

What is the physical/physiological difference between the two? — Michael

If you accept that mental "representations" exist… — Michael

…and if you accept that we have direct knowledge only of these mental representations… — Michael

…and if you accept that the qualities of these mental representations (smells, tastes, colours, etc.) are not (and are possibly unlike) the mind-independent properties of distal objects… — Michael

Just understand that your direct realism is not inconsistent with my indirect realism. They're the same position, just given different names. — Michael

I'm not speaking for Luke. He's far more eloquent and concise than I. — creativesoul