I agree that how humans use language is a state of affairs, but is there an ultimate arbiter of the truth of certain statements about the world, for example about the truth of empirical propositions? Are there objective
truths about physical nature, or are these truths relative to contingent and conventional linguistic states of affairs?
Is the claim that dinosaurs existed before anybody talked about them incoherent? What if we instead say that SOMETHING existed before language-using communities named and defined them, but we can’t say that they were dinosaurs , since that is a conceptual convention? — Joshs

Is a dinosaur a word or a type of extinct organism?

Do you need words to tell the difference between an elephant and a giraffe? Or can you do that by just looking at them? Can you tell the difference between the letters A and B? If so, then how are you distinguishing them - visually, audibly, etc.?

What about similarities? Are there not things in the world that share characteristics and some share more than others? It is these similarities that we are pointing at with our use of words. When some things are similar to some things and different than other things then it seems like it would be useful to use a common symbol to communicate those similarities and differences. Nothing is identical, sure. There is a difference between this elephant and that one, but the similarities and differences are what we talk about and what similarity and difference we are focused on or communicating at any moment is dependent upon the goal. When talking about elephants, we aren't focusing on the differences between each organism with a trunk and big ears. We are talking about all organisms with a similar trunk and big ears.

But let us take a look at this so-called natural kind. Natural kinds, when we examine them, almost always turn out to have boundaries which are to some degree arbitrary, even if the degree of arbitrariness is much less than in the case of a completely conventional kind
like “constellation”. — Joshs

If boundaries are arbitrary then the boundary between fact and convention is arbitrary. The boundary between letters, words, and sentences on this screen are arbitrary.

Stars are clouds of glowing gas,glowing because of thermonuclear reactions which are caused by the gravitational field of the star itself, but not every cloud of glowing gas is considered a star; some such clouds fall into other astronomical categories, and some stars do not glow at all. Is it not we who group together all these different objects into a single category “star” with our inclusions and exclusions? It is true that we did not make the stars as a carpenter makes a table, but didn't we, after all, make them stars? — Joshs

You're focusing too much on the boundaries as if they are more important than what is within those boundaries. Does the fact that the boundaries are blurry mean that everything else that isn't at the boundaries are arbitrary? There are many objects that fit neatly into the category, "star", while there are a few that lie on the boundary of that category because they share some visual characteristics with stars and also share some visual characteristics with planets. Not every object that we call, "star" lies on the boundary. When we talk about "stars" we are not talking about what is on the boundary, but what lies easily within it. The fact that similarities exist and that some objects share more similarities than differences with other objects is not something humans created. It is what allows us to categorize and use words as representations in the first place. If everything had an equal number of similarities and differences in relation to everything else then I could see language, and categories in general, being much less useful than they are now.

Now Goodman makes a daring extrapolation. He proposes that in the sense illustrated by these examples, the sense in which we “make” certain things the Big Dipper and make certain things stars, there is nothing that we did not make to be what it is. (Theologically, one might say that Goodman makes man the Creator.) If, for example, you say that we didn't make the elementary particles, Goodman can point to the present situation in
quantum mechanics and ask whether you really want to view elementary particles as a mind-independent reality. It is clear that if we try to beat Goodman at his own game, by trying to name some “mind-independent stuff”, we shall be in deep trouble.” — Joshs

There's a difference between making the stars and making the scribble that refers to stars as a means of communicating. Is a star a word or scribble or utterance, or is a star a thermonuclear globe of hydrogen and helium gas?

I think you're being too literal in your reading. They're just saying that the utterance "the cat is on the mat" is not the cat being on the mat. — Michael

And neither is a table on the rug the cat being on the mat. Words are not cats. Cats are not dogs. Mats are not tables. Saying a cat is not a word is no different than saying a cat is not a mat. Words, mats, cats, tables and dogs all exist in the world and are distinguished visually and audibly. There is nothing special about words in this regard that would make one think that they are separate from the world.

There is nothing special about words in this regard that would make one think that they are separate from the world. — Harry Hindu

And again, you're just being too literal in your reading. When others talk about a distinction between language and the world understand it as your oft-quoted distinction between a map and the territory.

And again, you're just being too literal in your reading. When others talk about a distinction between language and the world understand it as your oft-quoted distinction between a map and the territory. — Michael

As I pointed out before, the map is part of the territory, not separate. If the ones that are using the term, "separate" don't mean it literally, then they don't really mean that language is separate from the world, then what is it they do mean? Why use the term, "separate" if that isn't what they mean? Seems to me that there would be a different term that they could use - like what they actually do mean, if not separate.

As I pointed out before, the map is part of the territory, not separate. — Harry Hindu

Well, I have a map of the United States which is definitely not a part of the United States.

If the ones that are using the term, "separate" don't mean it literally, then they don't really mean that language is separate from the world, then what is it they do mean? — Harry Hindu

Exactly what I said before; the utterance "the cat is on the mat" is separate to the cat being on the mat.

You've denied any objective truth as correspondence, but now you say there is some sense of real truth, a "deeper notion of truth", but you haven't given any indication of what it is. Is it a subjective truth? If truth is simply "intricate and intimate interconnections in the way we interact with the world and each other", then the way I understand my relationship with you and the world is completely different from the way that you understand this relationship, and truth, it appears, would be completely subjective. Or do you propose some objectivity to these relations? In which case, I think we're back to what you denied above. — Metaphysician Undercover

I’m proposing an idea of truth as intersubjective , not simply subjective. Yes, each of us enters into relations of communication with others bringing with us our own personal perspective , but the ever evolving ‘intricate and intimate interconnections in the way we interact with the world and each other’ I described allows for a gradual convergence among personal perspectives , but not the complete disappearance of subjective perspective. Think of this subjectivity within intersubjectivity as variations on a common theme. They would be no basis for communication with anyone else if our inner perspectives were all at all times completely different from each other.

Intersubjectivity is different than objectivity. The former is a dynamic pattern of interconnective relationality that cannot be captured by a formula or rule capturing the whole. The latter looks for a rule, law , fixed description applying to some aspect of nature. Objectivity tries to ground fluid self-organization on some content external to it which is not fluid.

Well, I have a map of the United States which is definitely not a part of the United States. — Michael

In this instance "not part" means not in the U.S. which is a spatial relationship and "seperate" in this sense is the literal sense. I already pointed out words are not special in this regard.

Exactly what I said before; the utterance "the cat is on the mat" is separate to the cat being on the mat. — Michael

This doesn't address what I said. If you dont mean "separate" in the same way you mean "not part", then what do you mean? If you don't literally mean what you say, then what do you mean literally? The relationship between the scribbles and the cat and the mat is one of representation, not seperate. If you want to say that the scribbles are not the cat on the mat, that is trivial and useless to the conversation. Representation is what joins the scribbles and the cat and the mat, not separates them.

Philosophers create problems by misusing language.

Intersubjectivity is different than objectivity. The former is a dynamic pattern of interconnective relationality that cannot be captured by a formula or rule capturing the whole. The latter looks for a rule, law , fixed description applying to some aspect of nature. Objectivity tries to ground fluid self-organization on some content external to it which is not fluid — Joshs

Then your posts are objective because your posts are fixed descriptions about sone aspect of nature or reality, like the relations between writers, readers, words and what they represent.

Philosophers create problems by misusing language. — Harry Hindu

:up: Well said!
We certainly and absolutely need to read more often such general comments about philosophy!
The above applies very also to the discussions carried out in this and other philosophical fora and communities.

I’ve heard this many times. Where on earth do you get the idea that it is the far right in the U.S. that believes truth is something made up?
— Joshs

Kellyanne Conway denies Trump press secretary lied: 'He offered alternative facts' — Michael

Do you honestly think Kellyanne Conway is a postmodernist? What she said is what is called ‘spinning the truth’. Lies, half truths and manipulations are perennial elements of political discourse on both sides of the aisle. We do this to mislead the other side when we know they will not agree with our views or actions. I can assure you both Conway and Trump have very fixed core beliefs about the world very, very far removed from postmodernist thinking. But they’ll say whatever they need tot to fool you and keep you off the track. It may be better from their vantage if you buy into the idea that they are radical relativists, and you seem to be taking the bait.

If you want to say that the scribbles are not the cat on the mat, that is trivial and useless to the conversation — Harry Hindu

Not when you're arguing against certain brands of anti-realism which deny the "trivial" distinction that realists take for granted.

Then your posts are objective because your posts are fixed descriptions about sone aspect of nature or reality, like the relations between writers, readers, words and what they represent. — Harry Hindu

Another variation on the ‘ postmodernists are self-refuting because they make truth claims against objective truth’ meme.

Here’s the difference between an objective truth claim and a postmodern assertion. The former invokes a picture of the way things are. This picture consists of a specific, arbitrary content. The postmodernist is not offering a picture containing an arbitrary content. They argue that we are constant moving from one picture, one value content to another. It is not the particular claims, schemes, worldviews , objective definitions that the postmodernist is interested in describing , but the movement. And saying that they are ‘describing’ something is not quite accurate, as if they stood outside of this flow. Rather, the postmodernist is enacting change and movement in talking about it. Their assertions are self-reflexive, already caught up in and changed by the flow.

If there is anything a priori in what the postmodern is offering ( other than transformative movement
itself) it is that this flow can be faster or slower. We can become relatively stuck within a theoretical value system , and this is associated with alienation. fragmentation and unintelligibility. Or we can find ourselves in the midst of more fluid transformation in which new options and directions can become available to us. A postmodern philosopher is more of a salesman than a theoretician. They’re not presenting a contentful doctrine they are inviting us to enter into accelerated movement and see if we like it.

I am posting this on page 33 of the topic "Is there an external material world?", which is very close to 1000 responses!

I really wonder and cannot believe how could such a trivial and without real value or use --for me, of course-- question, the answer to which is more than obvious,, could arise such a huge interest and create such a huge discussion!

I know of course that threads use to deviate a lot from the subject of the topic and that a lot of "personal" discussions are going on, and that kind of things, but ... Really, this topic?

It's the other way around. Every negation holds within it its own assertion. — Harry Hindu

All you doing is stating the obvious that a negation is also an assertion; nothing to do with the point re dialectics that every idea contains (the seeds of) its own negation.

It makes no sense to say that language is in the world but separate from the world. — Harry Hindu

You are thinking too literally. Of course language use occurs within the world; but language allows for a conceptual separation between the world and ideas about the world. All we are doing here is exploring different possible ways of thinking about things.

What does it mean to be about something? Aboutness is a causal relationship. — Harry Hindu

No, aboutness is a logical relation of reference. Attempting to parse everything in terms of causation just doesn't work. That path leads to scientism, to the idea that we are nothing but chemical robots. It's an impoverished, pointless and indeed self-refuting, view of life, and especially of human life.

Your potted history missed the joke. Oh, well.

Where on earth do you get the idea that it is the far right in the U.S. that believes truth is something made up? — Joshs

Rather, I had in mind Frankfurt' analysis of bullshit. My point, which seems to need reiterating, is that they might dismiss truth in much the way you do, and hence your view is useless here; and regardless, drinking bleach will not cure COVID. That's all.

For the rest of your post, there's little there with which I would disagree. And little that addresses the topic. Your comment is a bit of lost diatribe.

I really wonder and cannot believe how could such a trivial and without real value or use --for me, of course-- question, the answer to which is more than obvious,, could arise such a huge interest and create such a huge discussion! — Alkis Piskas

:wink:

And this is the most recent of dozens of such threads.

Habit? My posts here are in the main written while drinking my morning coffee.

I’m proposing an idea of truth as intersubjective , not simply subjective. Yes, each of us enters into relations of communication with others bringing with us our own personal perspective , but the ever evolving ‘intricate and intimate interconnections in the way we interact with the world and each other’ I described allows for a gradual convergence among personal perspectives , but not the complete disappearance of subjective perspective. Think of this subjectivity within intersubjectivity as variations on a common theme. They would be no basis for communication with anyone else if our inner perspectives were all at all times completely different from each other. — Joshs

This looks more like justification than truth, to me, demonstrating that my perspective is compatible with yours. How does truth enter this picture?

Not when you're arguing against certain brands of anti-realism which deny the "trivial" distinction that realists take for granted. — Michael

It seems to me that even an anti realist can't deny the distinction between a visual of a cat and a visual of scribbles.

Here’s the difference between an objective truth claim and a postmodern assertion. The former invokes a picture of the way things are. This picture consists of a specific, arbitrary content. The postmodernist is not offering a picture containing an arbitrary content. They argue that we are constant moving from one picture, one value content to another. It is not the particular claims, schemes, worldviews , objective definitions that the postmodernist is interested in describing , but the movement. And saying that they are ‘describing’ something is not quite accurate, as if they stood outside of this flow. Rather, the postmodernist is enacting change and movement in talking about it. Their assertions are self-reflexive, already caught up in and changed by the flow. — Joshs

Objectivity is not limited to static pictures. You can describe an event objectively as well. Objectivity is simply a description of how things are and is independent of other people's agreement or disagreement with you. Are you not telling us how things are for everyone even if we don't agree with you?

Subjectivity is a category error where you confuse some aspect of the world with some aspect of yourself.

If truths were subjective then what reason would you have to share your subjective knowledge with someone else? After all we would subjectivity interpret your scribbles on the screen so there is no true or false way of reading the scribbles. No one can ever be wrong if truths are subjective, which is one reason some people find solace in believing in subjective truths - so they can avoid the stress of being wrong.

I am posting this on page 33 of the topic "Is there an external material world?", which is very close to 1000 responses!

I really wonder and cannot believe how could such a trivial and without real value or use --for me, of course-- question, the answer to which is more than obvious,, could arise such a huge interest and create such a huge discussion! — Alkis Piskas

I think most of it hasn't been to discuss whether or not an external material world exists, but what everyone means by, "external", "material" and "world". Threads like this tend to go on forever because we are all talking past each other and misusing terms. Some are artfully (not literally) using terms in playing word games and don't seem to have the intention of saying much of anything useful.

Very good point and nicely put. :up:
(You are maybe the only one who has thought about that. Well, maybe the poster too. :smile:)

Objectivity is not limited to static pictures. You can describe an event objectively as well. Objectivity is simply a description of how things are and is independent of other people's agreement or disagreement with you. Are you not telling us how things are for everyone even if we don't agree with you? — Harry Hindu

I appreciate that there are differing definitions of objectivity. My notion of objectivity, consistent with writers like Putnam, is not just the way things are independent of social consensus. It must assume intrinsic properties, substance , attributes associated with an object.To be an intrinsic property, it need not be permanent but only measurable, which means it must endure as self-identical for some period of time. Of course , properties of natural objects tend to be relational ( mass, spatial dimensions , energy, etc). Here we can say that the properties of objects are intrinsic to the system of relations producing them, which are therefore objective.

But if we were to say that the nature of objects is not only relative to human subjects before whom they appear, or relative to systems of relations with other objects, but that neither these objects nor their systems of relations have any intrinsic properties or attributes that can be measured, then these objects are no longer ‘objective’. They are events that only appear once as what they are and then change into new objects which only appear once ( and an object is itself only an instantaneous differential change). As Putnam says , “the metaphysical assumption that there is a fundamental di­chotomy between "intrinsic" properties of things and "relational" properties of things makes no sense.”

Objectivity then becomes a human conceptual process attributing intrinsic self-identical properties to events that never reproduce any aspect of what they are identically from one moment to the next. It is we who create the abstractions of intrinsically and reparable self-identity that we then attribute to an ‘objective’ world.
Natural events are changes in relations of change. When we interact with the empirical world in order to represent it , we are further changing this web of changes. As I said, even if we could
talk about what something ‘is’ in itself , independent of our interaction with it, we still cannot locate any object , process, system of relations in the world that simply ‘is’ what it is as a repeatable set of intrinsic properties, attributes, laws.

Subjectivity is a category error where you confuse some aspect of the world with some aspect of yourself.

If truths were subjective then what reason would you have to share your subjective knowledge with someone else? After all we would subjectivity interpret your scribbles on the screen so there is no true or false way of reading the scribbles. No one can ever be wrong if truths are subjective, which is one reason some people find solace in believing in subjective truths - so they can avoid the stress of being wrong. — Harry Hindu

As with objectivity , there are differing ways of understanding subjectivity. You seem to be thinking of it in the traditional sense of a kind of object , an inner substance with its own intrinsic properties partially insulated from the objective world. This inner substance is divided from , and places itself opposite objects of an outer world, It can represent this ‘objective’ world accurately or falsely, rationally or irrationally , subjectively or objectively.

My understanding of subjectivity comes from phenomenology, which dispense with this divide between inner and outer, subject and object. Subjectivity for them is not processes inside the head, locked away from
the world. Subjectivity is the zero point of an interactive process in which who and what I am , what I think and how I perceive the world, is remade every moment in some small fashion in the act of perception. Body, mind and environment make up one inseparable unity of continual reciprocal interchange and feedback. As subjectivity , I am this interactive environmental
system. To separate off an inner subject from its environment misses the point. There really is no such thing as a subject in this sense.

You say no one can ever be wrong if truths are subjective, but if subjectivity is a system of interactions between miind, body and world , it is a also a normative system. Think of an organism that is embedded within an environmental niche. The organism’s own behavior produces that niche by having certain aims and goals that define. what matters to it. The niche for an ant is irrelevant to that of a jaybird. Within the niche that an organism produces with its behavior, there are eight and wrong ways of functioning. There must be a continual effort at adjusting and adapting between organism
and niche for it to continue to survive, that is , to maintain it’s way of functioning.

The human cultural world is differentiated into many niches and subniches. Your subjective functioning and my subjective functioning represent interacting and overlapping subniches within larger cultural niches. So the way you interpret meaning will not duplicate
mine but they can and usually do interact closely enough for us to be able to form agreements and mutual
understandings. Science represent a widely shared niche within which we can come to agreement on practices of behavior. The essence of truth is in the relative stability and pragmatic usefulness of agreed upon conventions of practice , rather than in conformity of our representations with ‘intrinsic’ objective features of a world. Put differently, we cannot say that truth is conformity with intrinsic feature of an objective world when that world only exists for us as a niche that is co-defined by our own normatively organized interactions with it. The niche , like truth , is neither objective nor subjective in the traditional sense, but a dynamic interaction between the two poles.

I agree that how humans use language is a state of affairs, but is there an ultimate arbiter of the truth of certain statements about the world, for example about the truth of empirical propositions? Are there objective truths about physical nature, or are these truths relative to contingent and conventional linguistic states of affairs?

Is the claim that dinosaurs existed before anybody talked about them incoherent? What if we instead say that SOMETHING existed before language-using communities named and defined them, but we can’t say that they were dinosaurs , since that is a conceptual convention? — Joshs

I've often used a passage from Bryan Magee's book on Schopenhauer to argue this very point, based on Kant's claim 'if I were to take away the thinking subject, the whole corporeal world would have to disappear.' That leads to the interminable wrangle about trees in forests, railway cars with no wheels, and so on - the apparently preposterous idea that should I stop observing something, that it vanishes or ceases to exist.

After many debates about it, I express it like this: that the word 'exist' or anything that we designated as 'an existing thing' carries a concealed premise. The mind - not your or my mind in particular, but the mind - provides the setting, the stage, the point-of-view, within which anything we designate as 'existing' is meaningful. The sense in which anything exists 'outside' or 'apart from' that is a meaningless question.

It doesn't literally mean that nothing exists outside of the mind, but that the manner or sense in which it exists is unintelligible as a matter of definition. It's easy to imagine a world without any observer. But there's still a point of view implicit in that image, because it is ordered. There's an image of the planets, stars, the earth, sun, and so on. It might be a scientifically-precise image, informed by recent cosmology. But if you completely remove any point of view or perspective then there can be no image at all, nor any discrete objects or relationships - or even space and time, which depend on a sense of scale in order to be meaningful. All discussion of any subject - what happened just now, or at the beginning of the cosmos - is set against that implicit understanding, which is (as you say) the ineliminable 'subjective pole' of existence. The mistake of naturalism (articulated in Husserl's criticism) is to forget that (and isn't this the 'forgetfulness of being', of later phenomenology?)

Science represent a widely shared niche within which we can come to agreement on practices of behavior. The essence of truth is in the relative stability and pragmatic usefulness of agreed upon conventions of practice, rather than in conformity of our representations with ‘intrinsic’ objective features of a world. — Joshs

:up: I agree, but it's worth noting that in Greek philosophy, it was still held that true knowledge - knowledge of what truly is - is the ultimate end. In Buddhist philosophy it is the quality of sagacity (possessed by the Buddha) of yathābhūtaṃ, 'seeing it like it is', or of vidya 'true knowledge', or in Latin 'veritas' - there are various terms in different traditions. But that is not something contemplated by modern philosophy on the whole, due to the fragmentation of the various fields of knowledge.

Incidentally you may be interested in this article about the convergenges between Buddhism and phenomenology.

First, he noted that our sensations can only be said to be giving us some awareness of an external world if they in some way resemble it. If our sensations in no way resemble the world they're supposed to be telling us about, how do they give us any awareness of it? — Bartricks

Let's imagine for some time that there is a world with observers in it. That world is made up of a ridiculously high amount of extremely small particles. The observers of that world themselves are composed of a bunch of extremely small particles, and when taken as a whole, one observer is far larger than the smallest possible particle. Yet, the observers perceive this external world as made up of a bunch of objects, all approximately their scale, with some being larger than them, but not too large, and some being smaller than them, but not too small.

Their perception of their world then is quite different from the reality of it being a bunch of small particles. But strangely enough, even with this very inaccurate perception, they still manage to predict the behavior of the world around them with extreme precision. Are they aware of their world, despite it not being like their perception at all, or are they unaware of it ?

it was self-evident to reason that a sensation can only resemble another sensation. Sounds are like sounds, smells like smells, textures like textures and so on. — Bartricks

It seems that the argument you are presenting comes back quite often to the notion of a sensation resembling something. What does it mean exactly to say that a sensation resembles another ?

Next he held that it was also self-evident that sensations are essentially sensed. That is, they cannot exist unsensed.

Next, sensations are always and everywhere sensed by a mind of some kind. For any sensation, there is a sensor, and the sensor is a mind. — Bartricks

(Don't take this part as a serious objection, just consider it like a fun philosophical and maybe intellectual exercise, or else it will just complicate the whole issue even more by bringing in another issue):
Unless you're a Platonist. A Platonic response to this would be that the Form of sensation exists independently of sensations and their sensors and is a sensation by itself. Therefore, there is at least one sensation (the Form of sensation) that exists independently of a sensor. Unless you're one of those Platonists that think that the Forms are just ideas in the mind of God. But then again, Platonism is also idealism.

Imagine an air traffic controller looking at flashes of light on a circular screen and lots of numbers. Is the air traffic controller perceiving the planes he has so much information about and whose behaviour he can predict and direct? No. The air traffic controller is acquiring lots of true beliefs about some planes, but he is not perceiving them.
Or perhaps a better example might be a pilot. Pilots do not have to look out the window to fly the plane and navigate the landscape, as they have enough information from their instruments. But when the pilot is looking at the instruments they are not perceiving the landscape (unlike when they look through the window at it).

There is clearly a difference then between acquiring one's awareness via means that in no way resemble what one is becoming aware of and via means that do. And it is in the latter case that we can be said to be 'perceiving'. Or at least, that a necessary condition for perception has been met (resemblance isn't sufficient).

That's all Berkeley needs, for he is concluding that the world we perceive is made of sensations. There are, however, other features of reality that we do not perceive but are nevertheless aware of, such as minds.

I think resemblance is a sensation. I sense x to resemble y. There is a resemblance sensation experienced when I sense or think about x and y. And by hypothesis, in order for that sensation of resemblance to be of actual resemblance, it would need to resemble it (otherwise I would not be perceiving it). And only a sensation can resemble a sensation (a truth of reason). Thus actual resemblance is a sensation.

Re Platonism. I am not sure what to say about that. I suppose that a version of Platonism according to which the Forms are archetypes in the mind of God is entirely compatible with Berkeley's view.

Insofar as I understand Plato, the realm of the Forms does not resemble the sensible world. Rather, the sensible world 'reminds' us of the Forms. That's a different relation entirely.

So, if we are talking about what it takes for our sensations to be perceptions of a world, then there needs to be a world that resembles those sensations in order for them to constitute perceptual awareness of it. And that world would have itself to be made of sensations.

But perhaps understanding the world requires possession of a fund of concepts acquired from elsewhere. I think that's compatible with Berkeley's view.

Then it's not clear what you mean by saying that if there is a model of a cup then there must be a cup. — Michael

You can't model a figment of your imagination because there's no hidden states to infer the cause of. With your own (untrammelled) imagination there's only known states, the entire processes is within your Markov Blanket. To have a modelling process we need a hidden state, some element outside of our Markov Blanket to infer the cause of. The process of modelling entails a Markov Blanket which entails an internal/external divide in model network nodes.

This itself doesn't then entail an external material world, it only need be data-external to the modelling network, it needn't be physically external to that which houses the modelling network. That some things are indeed physically external is part of the model of the causes of our sensations of those things. The best explanation for the consistency of my expectations and your expectations about the cup is that there's an external cup. Such consistency is not present in Unicorns so a better explanation for my internal (but seemingly data-external) image of a Unicorn is that there's no such external object, but there is a shared cultural artefact from which the data originates (via spoken descriptions, paintings etc).

No, I'm not saying we model the model. The point is that the perception itself is understood as a model, or more accurately a process of modelling, and the end result is seeing what has been modeled. — Janus

Yes, we seem to be on the same page. What I'm arguing (just to, hopefully, clarify further) is that we cannot 'see' the model if the process of seeing involves making a model (but is not exhausted by making a model). It's like saying we digest chyme. We don't We digest food. Making chyme is part of the process of digestion, but it is not that which we digest. Making a model of the external world is part of the process of perception, it is not that which we perceive.

If one wants to argue (as some do) that there's no external world, then one would have to take issue with the meta-model (the Bayesian policy) that the causes of our sensations originate from an external world at all. Accepting that policy, however, 'seeing' is the process of inferring the external-world causes of the retinal sensations - ie the cup.



(Also in answer to @Joshs and @Wayfarer).The point about indirect realism (a point which seems to keep getting lost), is not to question this meta-policy (the assumption of an external world source of sensory stimuli), but to accept the influence of the stages in the process of perceiving these external world causes. The direct realist would have it that the process involves the data from the external-world cup entering our dat-processing system and our responding to it accordingly. Errors are non-systemic. The indirect realist holds that (among other components) there are two (or three) important steps in the process which have a material effect on how we can talk about the reality they model...

1) a Bayesian predictive modelling stage where the cause is inferred based on prior expectations (and, importantly) data is filtered according to those prior expectation as means of noise-reduction)

2) an active interaction with the inferred source of the data aimed at either gathering salient information to confirm/disconfirm the current hypothesis or at changing the external sources to better match the current hypothesis. (as @Joshs is wont to point out, this is a collaborative interaction, not a one way process). @Banno's 'Direction of fit' goes here.

3) a social activity aimed at ensuring your model of the external world is similar enough to my model of the external that your response to it is going to be more predictable for me (ie I reduce my surprise at your responses by unifying our models)

It seems as if I'm permanently caught between those ultra-realists who dispute the significance of (1) and those idealists who (off the back of my trying to defend (1)) think I'm opposed to the significance of (2) and (3). All three are part of the process of perception. The object of perception is the external world hidden state, the process involves sufficient interactive, predictive, and social stages to accommodate the various features of perception that idealists like to point out as evidence against realism.

1) a Bayesian predictive modelling stage where the cause is inferred based on prior expectations (and, importantly) data is filtered according to those prior expectation as means of noise-reduction) — Isaac

Are you familiar with quantum bayesianism?

Along with the researchers Carlton Caves and Rüdiger Schack, he interpreted the wave function’s probabilities as Bayesian probabilities — that is, as subjective degrees of belief about the system. Bayesian probabilities could be thought of as gambling attitudes for placing bets on measurement outcomes, attitudes that are updated as new data come to light. In other words, Fuchs argued, the wave function does not describe the world — it describes the observer. “Quantum mechanics,” he says, “is a law of thought.”

Quantum Bayesianism, or QBism as Fuchs now calls it, solves many of quantum theory’s deepest mysteries. Take, for instance, the infamous “collapse of the wave function,” wherein the quantum system inexplicably transitions from multiple simultaneous states to a single actuality. According to QBism, the wave function’s “collapse” is simply the observer updating his or her beliefs after making a measurement. Spooky action at a distance, wherein one observer’s measurement of a particle right here collapses the wave function of a particle way over there, turns out not to be so spooky — the measurement here simply provides information that the observer can use to bet on the state of the distant particle, should she come into contact with it. But how, we might ask, does her measurement here affect the outcome of a measurement a second observer will make over there? In fact, it doesn’t. Since the wavefunction doesn’t belong to the system itself, each observer has her own. My wavefunction doesn’t have to align with yours.

It aligns near enough to all practical purposes, but they're still subjective, to some degree.

Liebniz's law of identity
1. Identity of Indiscernibles

Law of equivalence
2. Equivalence of indiscernibles

It's obvious that the OP's question can't be answered either way (mind-created "external" worlds & true external worlds are indiscernible). However, they ain't identical! How do we tell the difference between A and B when there is no difference between the two, knowing full well that A $\neq$ B. Capgras delusion and related illnesses might provide vital clues, I dunno.

$\frac{1}{2} = \frac{1}{2}$ but $\frac{1}{2}$ $\equiv$ $\frac{33}{66}$.

Paradox!? Contradiction?!