while the direct realist is agreeing as to the science but pointing out the grammar. — Banno

Pointing out the grammar doesn't address the epistemological problem of perception, which is the problem that direct and indirect realists are trying to resolve. You seem to have just co-opted the label "direct realism" to describe something else entirely.

The very notion that perception, globally speaking, distorts reality is incoherent anyway, since it is only via perception that we get any notion of reality. Any supposed reality beyond the possibility of our perceiving it is, since unknowable, completely useless as a point of comparison. — Janus

As I said in my previous comment, you're reading too much into the phrase "distorts reality". That we naively assume that colours and smells and tastes are properties of things like lemons rather than just mental/bodily responses to stimulation isn't that the Standard Model and neuroscience cannot be trusted.

The science shows us that objects are constituted of atoms, that the surface atoms absorb and emit electromagnetic radiation of particular wavelengths, that this electromagnetic radiation stimulates the sense receptors in our eyes, that our eyes send signals to our brains, and that our brains then produce the conscious experience of colour. The science also shows us that in most humans in most lighting conditions, electromagnetic radiation with a wavelength of ~700nm is responsible for the experience of the colour red, but that differences in eye or brain structure can entail the experience of a different colour.

With respect to the epistemological problem of perception that gave rise to the distinction between direct and indirect realism, this is indirect realism.

Direct realism would entail something like A Naïve Realist Theory of Colour, which claims that "colours are mind-independent properties of things in the environment that are distinct from properties identified by the physical sciences" or like primitivism, which claims that "there are in nature colors, as ordinarily understood, i.e., colors are simple intrinsic, non-relational, non-reducible, qualitative properties. They are qualitative features of the sort that stand in the characteristic relations of similarity and difference that mark the colors; they are not micro-structural properties or reflectances, or anything of the sort."

These direct realists views have been refuted by the science of perception (and of the wider world).

One can imagine your creature's physiologist making the "discovery" that half the population sees things upside down, and their philosophers explaining carefully that no, they don't. — Banno

The philosopher would be wrong. The scientist knows best. They're the ones actually studying how the world and perception works.

Not so much. If the smell is only a thing constructed by the mind, then there is no reasons that lemons might not on occasion smell like mint. — Banno

The reason is that physics is mostly deterministic. The same stimulus is going to elicit the same response in the same organism. When taste receptors in the tongue interact with sugar then the same kind of electrical signal is sent to the brain which then processes it in the same sort of way, with the same mental phenomenon occurring as a result.

And if something in the tongue or the brain changes then the mental phenomenon will change.

And if your tongue or your brain is different to mine in the relevant way, then the mental phenomenon you experience when eating lemons will always be different to the mental phenomenon I experience when eating lemons. A lemon's taste to you would always be different to a lemon's taste to me.

See, for example, this:

A 2011 study by Cornwall College found that sprouts contain a chemical, similar to phenylthiocarbamide, which only tastes bitter to people who have a variation of a certain gene. The research found that around 50 per cent of the world’s population have a mutation on this gene. The lucky half don’t taste the bitterness usually associated with sprouts, and therefore like them a whole lot more than everyone else.

Again, no; the "object of their rational consideration" is the snake and the competing males. — Banno

Well, no. They both see the same thing - the world. They both see the snake coming to have one of them for dinner. They both see the competing males. — Banno

And when we both watch Biden's inauguration on TV (and in different rooms), we're both seeing the same thing; Biden's inauguration. And Biden's inauguration is indeed an object of our rational consideration.

But it's still indirect. The TV is an intermediary/more immediate. And then appearances a further intermediary and even more immediate.

Again, that lemons smell like lemons, and not like (say) mint. — Banno

That lemons smell like lemons is a vacuous claim that has no bearing on the arguments made by direct and indirect realists.

As Austin showed, the framing of the argument in those terms is muddled. — Banno

Then you're welcome to present Austin's arguments. I don't see how saying irrelevant things like "lemons smell like lemons" is helpful at all.

In fact, they see the world the same. — Richard B

They don't. Relative to each other, they see things upside down.

Imagine an organism with a peculiar sex difference; the males' eyes and the females' eyes are, relative to the other, upside down such that what the males see when standing is what the females see when hanging upside down, and vice versa.

The way the males see the world is very different to the way the females see the world (with respect to its orientation).

Imagine also that this organism is intelligent with a language. Both males and females use the same word to describe the direction of the ground and the same word to describe the direction of the sky.

And we can add to this by imagining differences in size (e.g. that one of the sexes has a magnified vision relative to the other) and colour (not to mention smell and taste).

The way they navigate and talk about the world is the same, and yet the way they see (and smell and taste) the world is very different. The appearance of the world is a mental phenomenon, and it is the appearance of the world that is the immediate object of their rational consideration.

This, to me, is closer to indirect than direct realism with respect to the epistemological problem of perception.

It is kind of annoying that you cannot italicize on mobile. There is room for a tweet icon, but not italics? — hypericin

You can if you turn your mobile to landscape.

As a conclusion based on the assumption that perception enables an undistorted picture, namely the scientific understanding of perception, it is a contradiction of the grounding assumption, and therefore self-refuting. — Janus

One of these must be true:

1. The science of perception is correct and suggests that perception distorts reality
2. The science of perception is correct and suggests that perception does not distort reality
3. The science of perception is incorrect and suggests that perception distorts reality
4. The science of perception is incorrect and suggests that perception does not distort reality

The science of perception suggests that perception distorts reality. So either (1) or (3) is true. So either perception distorts reality or the science of perception is incorrect.

But if perception does not distort reality then the science of perception would be correct. So if the science of perception is incorrect then perception distorts reality.

The above is a simple application of the law of excluded middle and of modus tollens, and without assuming anything about the reliability or perception, and so there's no contradiction.

The only contradiction is to argue that perception does not distort reality even though the science of perception suggests that it does.

Your only recourse is to argue that (2) is true, but then that would be to deny the existence of the actual empirical evidence.

Also, you're reading too much into "distorts reality". That we naively assume that colours and smells and tastes are properties of things like lemons rather than just mental/bodily responses to stimulation isn't that the Standard Model and neuroscience cannot be trusted.

Well, you might excuse me since it remains unclear to me what it is you are claiming. It seems to be something like that, since lemons sometimes smell lemony, therefore that is how they smell when nothing has a nose. — Banno

No, I'm making it explicit what "lemons smell like lemons" means, and explaining that this does not address the arguments made by either direct or indirect realists.

I'm also still trying to understand what you mean by saying that we smell things as they are. What does the "as they are" add to the claim that we smell things? Unless you're trying to argue that things like lemons have a smell even if nothing has a nose then it seems like a meaningless addition.

it means the effect already lies in the cause — LFranc

What does this even mean?

But overwhelmingly, lemons smell like lemons.

Seems some folk are perplexed by this. — Banno

Nobody is perplexed by this. It’s the vacuous claim that lemons cause me to experience what lemons cause me to experience.

It has no bearing on anything said by either direct or indirect realists.

How dod you get to that? — Banno

You said that we smell things as they are, which under any reasonable reading is to say that smells are properties of those objects that we are then able to detect.

The existence of organisms with noses has nothing to do with the properties of a lemon, and so if lemons have some property of smell then they have that property of smell even if no organisms have noses.

But lemons don't have smell properties of this kind. It is simply the case that lemons produce chemicals that cause humans (with functioning noses) to have a certain kind of olfactory experience (and likely cause non-human organisms to have a different kind of olfactory experience).

I haven't said the scientific understanding of perception is incorrect. I've said that if the assumption is that perception as such distorts reality then the scientific understanding of perception, which is itself based on perception, cannot be trusted. To trust it and base arguments on it, would on that assumption, be a performative contradiction. — Janus

If perception does not distort reality then the empirical evidence would show us that perception does not distort reality. The empirical evidence does not show us that perception does not distort reality. Therefore, perception distorts reality.

There's no performative contradiction in applying modus tollens.

I've said that if the assumption is that perception as such distorts reality then the scientific understanding of perception, which is itself based on perception, cannot be trusted.

That perception distorts reality isn't the assumption but the conclusion. We don’t start as indirect realists but as scientists and then accept what the empirical evidence tells us about how perception actually works. And that is that colours and tastes and smells are not properties of lemons but are a response to a lemon’s properties. The naive view that projects colours and tastes and smells onto lemons is mistaken.

In the context of this debate, there is no such thing as a direct experience of an external world object, since all such experiences are mediated by phenomenal experience. — hypericin

Direct realists recognize the difference between phenomenal experience and external world objects. So why do they still claim that perception of external world objects is direct?

In an every day context yes, but not in the context of this debate. — hypericin

In the context of this debate, what is required for an experience to be direct? In the context of this debate, is direct experience of an external world object only possible if that external world object is in physical contact with my brain/experience?

we do sometimes see (hear, touch, smell...) things as they are — Banno

So things have a smell even if nothing has a nose? I disagree. There's no such thing as smelling something as it is. It is just the case that some objects produce chemicals that stimulate some sense receptor of some biological organism, causing that organism to have an olfactory experience.

The naive realist view of projecting the properties of that olfactory experience onto that external world object is mistaken.

And the same principle with vision, e.g with colours.

I said nothing of the sort. — hypericin

You said that a direct experience is unmediated. You seemed to be suggesting that if there is some third physical thing in the causal chain between the experience and the external world object then the experience is mediated. The conclusion, then, is that the experience is direct if and only if there is no third physical thing in the causal chain between the experience and the external world object, i.e. that the external world object is in physical contact with the experience (or the brain activity upon which the experience supervenes?).

See my example of the baseball game. — hypericin

So when I'm watching at the stadium I have a direct perception of the game?

The distinction is about mediation. Is the experience mediated, so that it arrives second hand, via a more direct experience? Or is there no intervening layer of experience? — hypericin

So an experience of an external world object is direct if and only if the atoms that constitute that object are physically touching the atoms in my brain that constitute my experience (assuming, for the sake of argument, that experience is reducible to brain activity)? I don't think any direct realist claims that that is the case.

Direct realists claim that we directly experience objects that exist at a distance. So clearly they believe that experience is both mediated and direct, and so "direct" cannot simply mean "unmediated".

This seems like an anti-realist view?

"Blue" is definitional, in terms of wavelengths — AmadeusD

I don’t think that’s right. Particular wavelengths cause most humans in normal lighting conditions to see blue, and so as a matter of convention we might describe those wavelengths as “blue light” but it’s important to recognise that the term “blue” now has two different meanings.

In fact the very claim that two people see the dress to be two different colours requires that colour words (in this context) refer to the quality of the experience and not the wavelength of the light as the wavelength is the same for all of us.

Some colour realists seem to conflate these meanings.

Also there’s the photo of the dress that some see as black and blue and others as white and gold. Any “information” in the experience is influenced by the particulars of our bodies as well as the external stimulus.

How are we to know which parts of our experience provide us with “raw” information about the external world?

Perhaps this is the source of much of the disagreement. The debate is a factual one; about whether we do or do not perceive the world directly. The direct realist position is that we do perceive the world directly; the indirect realist position is that we do not. — Luke

Well, the first step is to explain what it means to experience something directly and what it means to experience something indirectly. Can "direct" and "indirect" be explained without simply being defined as not being the other?

Once that's done, I think it useful to consider senses other than sight. The preoccupation with only visual experiences is an uncritical approach.

So let's take olfactory experience. Do I smell a rose? Or do I smell the geraniol in the air, produced by the oils in a rose's petals? Must it be a case of either/or, or are they just different ways of talking about the same thing?

After that, we should ask if there's such a thing as a correct smell. Perhaps the way a rose smells to me isn't the way a rose smells to you. If there is a difference, must it be that at least one of us is wrong? This leads on to having to ask if, and in what way, smells are properties of roses. Do our noses enable us to experience a rose's "inherent" smell, or does a rose have a smell only because organisms have noses? If the latter then we might then ask if there's a difference between smelling a rose and experiencing a smell caused by a rose.

How would the direct and indirect realist each answer these questions?

And finally, is there something unique about visual experience such that noses and smells are fundamentally different (in the relevant philosophical sense) to eyes and e.g. colours.

It has nothing to do with somebody holding a secret. It has to do with putting a human in the box. — noAxioms

I was just trying to paraphrase the Wikipedia article.

However, unless Wigner is considered in a "privileged position as ultimate observer", the friend's point of view must be regarded as equally valid, and this is where an apparent paradox comes into play: From the point of view of the friend, the measurement result was determined long before Wigner had asked about it, and the state of the physical system has already collapsed. When exactly did the collapse occur? Was it when the friend had finished their measurement, or when the information of its result entered Wigner's consciousness?

The cat is not in a superposition there either — Benkei

It is according to some interpretations of quantum mechanics, e.g. Copenhagen, Von Neumann, and Many-worlds.

which in any case is not a state of being but a consequence of epistomological limitations of knowledge of a given system. — Benkei

I believe this entails local hidden variables, which have been disproven. Superposition isn't just an epistemological limitation but a literal fact.

The cat isn't in a superposition the particle triggering the poison is. The cat is either dead or alive upon opening the box. So the experience of the person is that he was alive in a box if he's still able to answer questions. — Benkei

I think this depends on whether or not something like objective-collapse theory is correct. If it's not then there's no "size limit" to a superposition. If a particle having one spin will result in one macroscopic outcome (the cat is dead) and the particle having another spin will result in another macroscopic outcome (the cat is alive), then the macroscopic outcome is in a superposition until measured.

From here:

According to objective collapse theories, superpositions are destroyed spontaneously (irrespective of external observation) when some objective physical threshold (of time, mass, temperature, irreversibility, etc.) is reached. Thus, the cat would be expected to have settled into a definite state long before the box is opened. This could loosely be phrased as "the cat observes itself" or "the environment observes the cat".

This is Wigner's friend.

Wigner observes John.

John measures a particle spin but doesn't tell Wigner the result.

From Wigner's perspective, is John in a superposition?

I will just say that my question remains unanswered — Philosopher19

I answered it. Neither p nor q make sense. @TonesInDeepFreeze has explained to you in depth that the sentence "A is a member of B in C" is meaningless in set theory.

the universal set is not contradictory in any way. — Philosopher19

This isn't about the universal set. This is about the Russell set. The Russell set is contradictory. It can neither include nor exclude itself without defying its own definition.

There are a number of set theories with a universal set, such as New Foundations and positive set theory.

I was being lazy because this discussion has gone on long enough. Should have been:

S = {S, …}

and

S = {x1, x2, …} where no xn = S

Russell’s paradox:

Assumption: S is the set of all sets that are not members of themselves.

Option 1:

S = {}

S is not a member of itself. But, as per the assumption above, it ought be a member of itself.

Option 2:

S = {S}

S is a member of itself. But, as per the assumption above, it ought not be a member itself.

Neither option 1 nor option 2 work. Therefore, the assumption is a contradiction.

Your p and q make no sense in set theory. Only 3a is meaningful in set theory (although as already mentioned, the “in B” part of the sentence is vacuous). And using that meaning, the set of all sets that don’t contain themselves is a contradiction. Russell proved this.

Whatever you’re trying to argue has nothing to do with Russell’s paradox and nothing to do with set theory.

When a set is a member of another set it is still a set with members of its own.

Given this:

A = {A}
B = {A, 1}

One of these must be true:

1. In B, A isn't a set
2. In B, A is a set with 0 members
3. In B, A is a set with 1 member, and that member is itself
4. In B, A is a set with 1 member, and that member isn't itself
5. In B, A is a set with more than 1 member, one of which is itself
6. In B, A is a set with more than 1 member, none of which is itself

So which of these claims are you making? It must be one of them.

The correct answer is (3):

A = {A}
B = {A, 1} = {{A}, 1}

So how does it follow that L has n-1 members in LL? — Philosopher19

You said that L is a member of itself "in L" but not a member of itself "in LL". So you're saying that L "in L" has one more member (itself) than L "in LL".

Which is nonsense.

If L has $n$ members then L has $n$ members "in L" and L has $n$ members "in LL".

Again, L is not a member of itself in LL (even though it is in LL because it is a member of itself in L). L is only a member of itself in L. — Philosopher19

This is wrong.

1. L is a member of L.
2. L is a member of LL.
3. L is a member of L "in LL"

4. January is a member of Months
5. Months is a member of L
6. January is a member of Months "in L"

Let's make this simple:

A = {A}
B = {A, 1}
C = {{}, 1}

When A is a member of B, is A the empty set?

The answer is no. "In B" the set A contains itself as the only member.

Your position entails that B = C, which is false.

When in fact B = {A, 1} = {{A}, 1}

Here's some JavaScript code to demonstrate:


Can test here. Click "Run" in top left. Bottom right will show "true".

Does L list itself in LL?
Is L a member of itself in LL/not-L? — Philosopher19

What is the difference between asking if L lists itself and asking if L is a member of itself?

I'm not asking how many members does x or y have. So I don't see how your example is relevant to what I asked. — Philosopher19

If L is a member of itself "in L" but not a member of itself "in LL" then L has $n$ members "in L" and $n - 1$ members "in LL".

But this makes no sense. A set is defined by its members.

If L has $n$ members then it has $n$ members "in L" and it has (the same) $n$ members "in LL".

So if L is a member of itself then it is a member of itself "in L" and it is a member of itself "in LL".

L = The list of all lists
LL = The list of all lists that list themselves

1) In which list does L list itself?
2) In which list is L a member of itself?

Can you answer both questions consistently and non-contradictorily? — Philosopher19

Let's consider these four lists:

Months

• January
• February
• March
• April
• May
• June
• July
• August
• September
• October
• November
• December

Planets

• Mercury
• Venus
• Earth
• Mars
• Jupiter
• Saturn
• Uranus
• Neptune

Lists

• Months (January, February, ...)
• Planets (Mercury, Venus, ...)
• Lists (Months, Planets, Lists, Lists that list themselves)
• Lists that list themselves (Lists, (?) Lists that list themselves)

Lists that list themselves

• Lists (Months, Planets, Lists, Lists that list themselves)
• (?) Lists that list themselves (Lists, Lists that list themselves)

Q1. How many members does Months have?
A1. 12

Q2. How many members does Months have when it is a member of Lists?
A2. 12

Q3. How many members does Planets have?
A3. 8

Q4. How many members does Planets have when it is a member of Lists?
A4. 8

Q5. How many members does Lists have?
A5. 4

Q6. How many members does Lists have when it is a member of Lists?
A6. 4

Q7. How many members does Lists have when it is a member of Lists that list themselves?
A7. 4

Q2, Q4, Q6, and Q7 are redundant/confused questions. We only have to consider Q1, Q3, and Q5.

So returning to your questions, they should simply be:

1. Does L list itself?
2. Is L a member of itself?

Assuming that these mean the same thing, the answer to both is yes. L lists itself/is a member of itself.

And so it is also listed by/a member of LL.

So, numbers start at one. — Zolenskify

You're half right.

A subject (you) smells some direct object (smoke, for instance). — NOS4A2

Saying that John smells smoke doesn't explain what it means for John to smell smoke.

The word refers to an external object. If you were to point at that object you would never point internally. The direction towards which your eyes face, in combination with measurable distance between you and that object, never reveal that any of it is internal, and in fact prove the opposite. — NOS4A2

And yet I see and talk about Joe Biden without ever being anywhere near him. The point I am making is that this supposed connection between what I see (and talk about) and the (meta)physics/epistemology of perception is a false one. You're getting stuck on an irrelevancy.

Pain is neither a thing nor a property. It is a noun, sure, but it is without a referent. — NOS4A2

Pain is very real. I don't know what else to say. You're lucky if you've never felt it.

But what it is one is seeing... — NOS4A2

I think the question isn't clear. What does it mean to say that I smell some X?

I agree with a lot of what you said there about the over-concern with the language. But what it is one is seeing, and what object in the world that noun ought to refer too, is important and relevant; and if the indirect realist is unable to state what that is, then the ideas are immediately lacking.

When I see Joe Biden on TV I am seeing Joe Biden on TV, and the term "Joe Biden" refers to the man who is the President of the United States.

I don't see how this addresses the (meta)physics or epistemology of perception. In fact I think it highlights precisely how the attention to how we ordinarily describe perception is misplaced.

A term like “pain” is a sort of folk biology. Maybe one feels a pinched nerve or some other malady that would reveal itself upon closer examination. If true, the latter ought to supersede the former as a more accurate accounting of reality. — NOS4A2

We might disagree over whether or not pain is a physical or non-physical thing, but whatever it is it is real and we feel it, so I don't see how this amounts to folk psychology.

Perhaps physicalism is correct and that pain is reducible to the firing of C-fibres. It still entails that pain isn't a property of the external world object (e.g. fire) that is causally responsible for the firing of those C-fibres. The indirect realist will say the same about tastes and smells and sounds and colours. They're reducible to some bodily function (whether it be in the brain or in the ears or in the eyes), not to some property of the external world objects that are causally responsible for these bodily functions.

Well that is certainly true. That and we often fail to consider how other people are using the terms "direct" and "indirect." — Count Timothy von Icarus

I made much the same point here in another recent discussion.

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).