You seem to assign some meaning to the word "event" that I don't understand. — fishfry

Would you prefer the term "act"? It is metaphysically impossible for an infinite succession of acts to complete.

Have you even looked up supertasks? I don't know how you can confuse them with mathematical sets.

Do you deny infinite mathematical sets? — fishfry

No. An infinite set is not an infinite sequence of events. An infinite sequence of events would be counting every member of an infinite set. It is metaphysically impossible to finish counting them.

Mathematically that's not true. The set {1, 2, 3, 4, ...} contains all the natural numbers, but there's no last number. — fishfry

That's not relevant to the claim I'm making.

I'm saying that if I have finished counting the members of some set then some member must be the final member I counted.

And besides, eternal inflation posits a temporally endless universe. It's speculative, but it's part of cosmology. Serious scientists work on the idea. So at least some scientists are willing to entertain the possibility of a physically instantiated infinity. — fishfry

I don't deny the possibility of something not ending. The issue is that supertasks entail that there is an end to infinity, which is nonsense.

You keep repeating that, but you have no evidence or argument. — fishfry

Thomson's lamp, my box changing colour, the example of writing out each natural number, etc. I've offered plenty. Your attempt to rebut them by reference to mathematical limits fails to address the issue.

You're continuing to argue against a position I don't hold. Why are you doing this? — fishfry

Because I'm arguing against the possibility of a supertask. You're the one who interjected with talk of mathematical limits. I'm simply responding to explain that this doesn't address the concern I have with supertasks.

I would, however, disagree with you that being inconsistent with known physics is the same as logical impossibility. — fishfry

I'm not saying that it's the same. I'm saying that as well as being a physical impossibility, supertasks are also a metaphysical impossibility.

No physical law can allow for an infinite sequence of events to be completed. The very concept of an infinite sequence of events being completed leads to a contradiction. To claim that it is metaphysically possible to have finished writing out an infinite number of natural numbers but also that there is no final natural number that I wrote is to talk nonsense.

If I finished writing out any number of natural numbers than there will be a final natural number and that natural number will be a finite number. This is a metaphysical necessity.

or else we’d be able to describe with some degree of accuracy what is actually going on in there. — NOS4A2

That's precisely what we are doing when we describe the pain we feel and the colours we see and the voices we hear when we dream or hallucinate.

We might not be able to describe it in neurological terms (e.g. "such and such neurons are firing"), but then that's why I'm not entirely convinced by eliminative materialism and am open to property dualism.

Even if you disagree with "perception" being the appropriate word to use for dreams and hallucinations, surely you have to accept that when we describe what's going on when we dream and hallucinate we're describing what's happening to/in us and not what's happening elsewhere in the world. The indirect realist simply argues that the same can be true of veridical experience because veridical experience, hallucinations, and dreams are all of a common kind – mental states with phenomenal character – that differ only in their cause (which is not to say that we can't also talk about their cause).

Experience is an act where the “distal objects” that we experience are acted upon in a certain way. — NOS4A2

This isn't what naive or indirect realists mean by "experience". They are referring to a particular kind of mental state with phenomenal character. These are, we now know, what occur when the appropriate areas of the brain are active, e.g. the visual and auditory cortexes.

Take this:

Disjunctivists and their opponents agree that veridical perceptions, illusions and hallucinations have something in common, in so far as they agree that such mental events should be grouped together as being perceptual experiences. They also agree that there are differences to be marked between them, hence the different labels for them. However, they disagree when it comes to specifying what these commonalities and differences consist in.

...

Some disjunctivists claim that veridical perceptions have a phenomenal character that hallucinations cannot possess. For example, according to one version of naïve realism (what we might call ‘naïve realism about phenomenal character’), when one veridically perceives the world, the mind-independent items perceived, such as tables and trees and the properties they manifest to one when perceived, partly constitute one’s conscious experience, and hence determine its phenomenal character.

...

The disjunctivist may insist that in a case of genuine perception, even if the objects of perception are distal causes of the subject’s experience, they are also figure non-causally as essential constituents of it. So the occurrence of the relevant brain processes won’t be sufficient to produce the kind of mental event involved in perception, unless further non-causal conditions necessary for the occurrence of that kind of mental effect also obtain.

It's not clear to me that your account addresses anything of relevance. It simply uses the term "experience" to refer to a causal chain of events that connects some distal object to the body and then asserts (without really any meaning) that this connection is "direct". As it stands it's not something that either naive or indirect realists will disagree with; it simply redefines the words used.

They say only that it seems that way — Luke

The first quote says that it seems to be that naive realism is correct; specifically "visual experiences seem to have the NR [Naïve Realist] property."

It doesn't say that naive realism just claims that things seem to be a certain way. You're misreading the quote.

or that our perceptions are shaped by those objects. — Luke

"... where this is understood in a constitutive, rather than merely a causal, sense."

None of these quotes state or even suggest that the naive realism position is that their perceptions have the same physical constituents as the perceived object. — Luke

As well as the aforementioned, there's also "for the naive realist, insofar as experience and experiential character is constituted by a direct perceptual relation to aspects of the world, it is not constituted by the representation of such aspects of the world" and "what is fundamental to experience is something which itself cannot be explained in terms of representing the world: a primitive relation of presentation."

Naive realists claim that it is the distal objects themselves, not mental representations, that are the constituents of experience.

And I'll add another from The Disjunctive Theory of Perception:

It follows that on a naïve realist view, the veridical perceptions and hallucinations in question have a different nature: the former have mind-independent objects as constituents, and the latter do not.

Your author of Semantic Direct Realism does not define naive realism (GDR or PDR) in terms of the physical constituents of percepts. — Luke

He says this:

For the naïve realist, the realism and the directness is enshrined in the fact that the phenomena are intrinsic features of the object itself—they are how the object is in itself. The semantic direct realist is agnostic about how the phenomena relate to the object, but asserts that the experience constituted by the phenomena subjectively embodies information putatively about something external. This leaves open the possibility of raising questions about the relation of the phenomenal qualities of which we are aware in perception, and the object about which we are directly informed in perception: are they intrinsic to it as PDR claims, or are they more remote from it.

And while I'm quoting him, I'll add this which gets to the heart of the matter:

In Brewer’s case, however, it is the object per se with which one is directly acquainted (see (i) below.). On the one hand, this avoids the straightforward form of the illusion argument, as I have just stated it: on the other, it leaves the status and role in perception of the object’s sensible qualities still to be articulated. It also arouses the thought that the sense in which it is some external object which is the object of acquaintance is more logical than phenomenological: what would it be for the object to be phenomenologically present—in a sensory form—if none of its sensible properties are directly presented? As nowadays it is permitted to believe in cognitive phenomenology, one might assimilate the direct perception of objects without the direct perception of their sensible properties to that category. But that is precisely a form of semantic direct realism: the directness consists in something more akin to a proposition or a judgement. It is as if the theory is that in all perceptual-type experience there is an at least immanent judgement (conceptual or not) and that judgement has as its object something purportedly in the world. This is SDR and is, as we shall see, also something that a sense-datum theorist can accept.

Why can't naive realists simply hold the view that distal objects have the properties that they perceive them to have? I find your view that naive realists hold the view that their perceptions have the same physical constituents as the perceived object to be a strawman. Where did you get this idea from? — Luke

What’s so naïve about naïve realism?

The second formulation is the constitutive claim, which says that it introspectively seems to one that the perceived mind-independent objects (and their features) are constituents of the experiential state. Nudds, for instance, argues that ‘visual experiences seem to have the NR [Naïve Realist] property’ (2009, p. 335), which he defines as ‘the property of having some mind-independent object or feature as a constituent’ (2009, p. 334), and, more explicitly, that ‘our experience […] seems to have mind-independent objects and features as constituents’ (2013, p. 271). Martin claims that ‘when one introspects one’s veridical perception one recognises that this is a situation in which some mind-independent object is present and is a constituent of the experiential episode’ (2004, p. 65).

Naïve Realism

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.

The Problem of Perception

For the naive realist, insofar as experience and experiential character is constituted by a direct perceptual relation to aspects of the world, it is not constituted by the representation of such aspects of the world. This is why many naive realists describe the relation at the heart of their view as a non-representational relation. This doesn’t mean that experiences must lack intentional content, but it means that (a) insofar as appeal is made to presentation to explain character, no appeal is made to intentional content for that purpose, and (b) what is fundamental to experience is something which itself cannot be explained in terms of representing the world: a primitive relation of presentation.

A Naïve Realist Theory of Colour

This book develops and defends the view that colours are mind-independent properties of things in the environment that are distinct from properties identified by the physical sciences.

I don't know of any physical/physiological difference. — Luke

So either there is some non-physical/non-physiological difference or there is no difference at all and the way you're trying to frame the issue is a confusion.

Is it your position that our perceptions of real objects are mediated by mental representations or not? — Luke

This is my position. I've been very clear on this for the past 40-odd pages.

If mental representations do not mediate our perceptions of real objects, then our perceptions of real objects are not indirect, they are direct. — Luke

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

I don't know what to tell you. 60 seconds can pass without anyone measuring it. If you can't accept this then we can't continue.

You know where your hand is at the moment. Do you know this indirectly? What could that mean? How is proprioception indirect? — Banno

It's what I said above:

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.

This is true even for proprioception (notwithstanding that "distal object" isn't quite the correct term to use when referring to one's hands), given that proprioceptive errors are possible.

I feel pain, pain is a percept, therefore I feel a percept. Nothing about this entails a homunculus. The schizophrenic hears voices and I see things when I dream. You are reading something into the grammar of "I experience percepts" that just isn't there and so inventing a strawman for indirect realism.

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.

Which is precisely why so-called "non-naive direct" realism is consistent with indirect realism. See Semantic Direct Realism.

The upshot is that indirect realism doesn't get the scientific stamp of approval its fans so desire. — Banno

This is what the science of perception shows:

The process of perception begins with an object in the real world, known as the distal stimulus or distal object. By means of light, sound, or another physical process, the object stimulates the body's sensory organs. These sensory organs transform the input energy into neural activity—a process called transduction. This raw pattern of neural activity is called the proximal stimulus. These neural signals are then transmitted to the brain and processed. The resulting mental re-creation of the distal stimulus is the percept.

To explain the process of perception, an example could be an ordinary shoe. The shoe itself is the distal stimulus. When light from the shoe enters a person's eye and stimulates the retina, that stimulation is the proximal stimulus. The image of the shoe reconstructed by the brain of the person is the percept. Another example could be a ringing telephone. The ringing of the phone is the distal stimulus. The sound stimulating a person's auditory receptors is the proximal stimulus. The brain's interpretation of this as the "ringing of a telephone" is the percept.

This is indirect realism, not naive realism.

Distal objects and their properties are not constituents of visual or auditory or olfactory experience.

But none of this is relevant to the point being made.

Naive realists claim such things as this:

The second formulation is the constitutive claim, which says that it introspectively seems to one that the perceived mind-independent objects (and their features) are constituents of the experiential state. Nudds, for instance, argues that ‘visual experiences seem to have the NR [Naïve Realist] property’ (2009, p. 335), which he defines as ‘the property of having some mind-independent object or feature as a constituent’ (2009, p. 334), and, more explicitly, that ‘our experience […] seems to have mind-independent objects and features as constituents’ (2013, p. 271). Martin claims that ‘when one introspects one’s veridical perception one recognises that this is a situation in which some mind-independent object is present and is a constituent of the experiential episode’ (2004, p. 65). — https://link.springer.com/article/10.1007/s11098-021-01618-z

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. — https://www.oxfordbibliographies.com/display/document/obo-9780195396577/obo-9780195396577-0340.xml

colours are mind-independent properties of things in the environment that are distinct from properties identified by the physical sciences — https://academic.oup.com/book/5610

Indirect realists reject these claims, and the science of perception supports this rejection.

That's all there is to it.

How is it an inference, then, and not a sentiment, or a mere prejudice? — Banno

My belief that my experiences are caused by distal objects is a "prejudice". My belief that a distal cow exists is inferred from a) my "prejudice" that my experiences are caused by distal objects and from b) I experience a cow.

It's not based on anything. It's just what seems most reasonable to me. I don't pretend that it's anything more than that.

Yes. It's more reasonable than "an evil demon is deceiving me".

Ah. SO you induce the existence of the world by application of "scientific method"?

SO does this method involve falsification, or is it statistical? — Banno

I believe in the existence of distal objects because I believe that the existence of distal objects best explains the existence and regularity and predictability of experience.

And you deduce, or perhaps infer, the existence of the world, including the things around you, from what the senses present to you?

How does that work? — Banno

Are you asking how induction and the scientific method work?

Yes. Indirect realists aren't idealists. They're realists. They just recognize, contrary to the claims of naive realism, that mental phenomena exist, that distal objects and their properties are not constituents of mental phenomena, that many (even all) of the properties of mental phenomena are not properties of distal objects, that many (even all) of the properties of mental phenomena do not even resemble the properties of distal objects, and that we have direct knowledge only of mental phenomena.

Yes.

Do you agree that sensory experience provides us with knowledge of the things around us? — Banno

It provides us with knowledge that there are things around us and that our bodies respond in such-and-such a way to sensory stimulation, but that's it.

Naive realists falsely claim that we know more than this because they falsely claim that distal objects and their properties are constituents of sensory experience. Indirect realists reject these claims.

Again, this is a bad question. — Banno

No it's not. It's a pertinent question that seeks to address the extent to which our body's physiological/psychological response to sensory stimulation allows us to form justified beliefs about the existence and mind-independent nature of distal objects.

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 mental representations existing and not being mediations and mental representations existing and being mediations?

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.

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.

Not all direct realists hold that color is a mind-independent property of distal objects. — creativesoul

I'm not arguing against direct realism. I'm arguing for indirect realism and against naive realism. Much of my time has been spent trying to explain that non-naive direct realism seems consistent with indirect realism: see Semantic Direct Realism.

Nobody is questioning the fact that 1/2 + 1/4 + ... = 1.

This is an example of a supertask:

I write down the first ten natural numbers after 30 seconds, the next ten natural numbers after 15 seconds, the next ten natural numbers after 7.5 seconds, and so on.

According to those who argue that supertasks are possible I can write out infinitely many natural numbers in 60 seconds.

Examples such as Thomson's lamp show that supertasks entail a contradiction. So even though it is true that 30 + 15 + 7.5 + ... = 60, it does not follow that the above supertask is possible.

It makes no sense to claim that I stopped writing out the natural numbers after 60 seconds but that there was no final natural number that I wrote.

what is "the epistemological problem of perception" — Banno

Does sensory experience provide us with direct knowledge of distal objects and their mind-independent properties?

Naive realists claim that it does because they claim that distal objects and their mind-independent properties are constituents of sensory experience.

Indirect realists claim that it doesn't because they claim that distal objects and their mind-independent properties are not constituents of sensory experience; they only causally determine sensory experience, and so the properties of sensory experience (e.g. smells and tastes and colours) may not resemble the mind-independent properties of distal objects.

Back on page one I said: "This argument is interminable because folk fail to think about how they are using 'direct' and 'indirect'." — Banno

And as I said back on page 1:

So to avoid using the terms "direct" and "indirect", my own take is that we have an experience that we describe as seeing an apple, but that the relationship between the experience and the apple isn't of a kind that resolves the epistemological problem of perception (or of a kind that satisfies naive colour realism, as an example). — Michael

The science is accepted by both "sides". You still haven't come to terms with that simple fact. — Banno

The science does not support naive realism.

Undefined by the description. That is to say, the color of the box afterwards is not a defined thing, which is different than it displaying the color of 'undefined'. — noAxioms

And so it is meaningless to claim that such a supertask can complete. The fact that we can sum an infinite series is a red herring.

Says the guy who has spent weeks asserting that direct realism is false because it denies indirect realism. — Banno

I haven't said that. I've said that the science of perception supports indirect realism and not naive realism.

there are no seconds unless measured out — Metaphysician Undercover

Yes there are. A second is "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom". This occurs even if we don't measure it.

Yet again you can't seem to get beyond our use of labels to understand that our labels refer to things that exist and do things even when we're not around.

Odd that all that color matching can be successfully achieved by a brainless machine. — creativesoul

It's not odd at all. We build it to measure the wavelength of light and then program it to output the word "red" if the wavelength measures 700nm.

This doesn't entail naive colour realism.

If the cow is in the field, then it is not in the brain. If we see the cow, then we see things that are not in the brain. The cow is one of the things we see.

What scientific account of ocular nature forbids us from seeing cows in fields? — creativesoul

As I have said before, I accept that we see cows.

But this has nothing to do with the dispute between naive and indirect realists. The dispute between naive and indirect realists concerns whether or not distal objects and their properties are constituents of the phenomenal character of conscious experience. Naive realists claim that they are and indirect realists claim that they're not. I think the science supports the claim that they're not.

I don't want to keep repeating myself.

What scientific account of ocular nature forbids seeing things that are not in the brain? — creativesoul

I don't know what you mean by "seeing things".

All I am saying is that visual experiences occur when there is appropriate activity in the visual cortex, that distal objects are often causally responsible for these visual experiences, and that these distal objects are not constituents of these visual experiences – and I think the science of perception supports this view.

What concerns us is the "conscious 'phenomenal' character of ... experience". I would say that the evidence strongly suggests that the conscious 'phenomenal' character of experience is either reducible to brain activity or supervenes upon it, neither of which allow for distal objects and their properties to be constituents. The connection between the two is merely causal.

I do not see how scientific evidence refutes 2. The emphasized part needs unpacked. — creativesoul

The important part is this: “… where this is understood in a constitutive, rather than merely a causal, sense.”

Distal objects like cows are causally responsible for the activity in my visual cortex, and so the resulting visual experience, but they are not constituents of that resulting visual experience.

To claim that distal objects are constituents of visual experience is to assert an unscientific account of visual experience.

I'm going to quote from Naïve Realism:

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."

Those who call themselves non-naive direct realists seem to want to accept the first part but reject the second part, but I can't make sense of the first part except as the second part.

So the relevant considerations are whether or not these are true:

1. Everyday material objects, such as caterpillars and cadillacs, have mind-independent existence
2. 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
3. These objects possess all the features that we perceive them to have

If (1) is true and (2) true then direct realism is true (and (3) is true).
If (1) is true and (2) is false then indirect realism is true (even if (3) is true).

I think the scientific evidence supports the claim that (1) is true and that (2) and (3) are false. Therefore, I think the scientific evidence supports indirect realism.

I meant better options than just indirect realism(indirect perception) as compared/contrasted to naive realism. There are more choices than just indirect realism that presuppose all components of all experience is/are located in the brain. — creativesoul

This is where I think there's confusion.

Naive realists claim that distal objects are constituents of experience. Indirect realists claim that distal objects are not constituents of experience.

Either distal objects are constituents of experience or distal objects are not constituents of experience.

Therefore, either naive realists are correct or indirect realists are correct.

What third option is there?

I think that there are better options... — creativesoul

Either naive realism is true or naive realism is false. It's a simple dichotomy.