Which one, right ? — Pie

Might be the day before you came here that everyone was quoting

3.1431 The essence of a propositional sign is very clearly seen if we imagine one composed of spatial objects (such as tables, chairs, and books) instead of written signs. Then the spatial arrangement of these things will express the sense of the proposition. — the big W

at each other.

I'd say the quoted part is some specific act of assertion, and the disquoted part is a state of affairs that corresponds to the assertion. — Tate

Still? You're still saying the disquoted part of a sentence is a disquoted part of the world, whatever that means?

My question is: how does (the meaning of ) a true statement depict reality ? What is this representational, optical metaphor doing or trying to do ? — Pie

I seem to recall, someone had a theory about that.

It would be some state of the world. — Tate

What would? What you're calling "the disquoted part"?

Some state of the world is a disquoted part? Part of what? Part of the world?

So "part" didn't mean "part of the T schema"?

You have to specify the context in which you're using the T-sentence rule. Is it Tarski? Redundancy? Are you try to make into correspondence theory? — Tate

Er,

If you're interpreting the t-sentence rule as a rendering of correspondence theory, then — Tate

Now then, in that context, your context, did

the disquoted part — Tate

refer to the sentence constituting the second part of the biconditional or to some corresponding event or relation, or something else, or all 3 (because it doesn't matter)?

I think we humans are pretty good at doing that too. — Pie

Let's see...

I wasn't trying to use it. I took Banno to be asking if we should interpret the quotes as signaling a specific act of assertion. My answer was that you can do that, you just need to explain that to the reader. — Tate

Ok so you were talking mainly about the first half of the biconditional. Even so, did

the disquoted part — Tate

refer to the sentence constituting the second part of the biconditional or to some corresponding event or relation, or something else, or all 3 (because it doesn't matter)?

I definitely need that explained.

I just meant that we can still drop "proposition".

My point was that you need to look for how an author is using the t-sentence rule. Use varies. — Tate

I was asking how you were trying to use it. Whether

the disquoted part — Tate

referred to the sentence constituting the second part of the biconditional or to some corresponding event or relation, or something else, or all 3.

Glad to hear it.

Then why say "both"?

Meh... Why would propositions be timeless? — Olivier5

You said

Is truth a property of sentences (which are linguistic entities in some language or other), or is truth a property of propositions (nonlinguistic, abstract and timeless entities)?
— Pie

Both, because propositions are in fact a class of sentences. — Olivier5

propositions are in fact a class of sentences. — Olivier5

Sure. But a sentence is already a class: of tokens, or copies. So you don't need another name for the more inclusive class.

Allowing translations into the class won't matter at all if they are parsed and interpreted the same. It's no different to letting symbols stand for the sentence-parts.

If you want a proposition to be a class of differently parsed paraphrases, then, why? And what? Non-linguistic? Abstract? Timeless?

and the disquoted part is a truth maker. — Tate

Not so fast. The sentence in the second part is a truth maker? Or it picks out a truth maker?

Seems to me the problem stems from treating propositions as individuals.
— Banno

Why is that problematic? — Tate

How is it clear? Is such an individual: truth-bearing sentence, truth-making event or relation, or something in between, or (as so often carelessly implied) all at once.

Tarski offers this example:

The sentence "snow is white" is true if, and only if, snow is white. — Michael

Quite. "Sentence" is fine. Drop "proposition". (Everyone!) If not why not?

there's just true claims ? — Pie

Yes. No corresponding relations or properties.

I think N is the wrong way to go. I think we agree ? — Pie

Yes if N is a totality of corresponding facts. No if it's a totality of things that I ought to tidy. But they correspond merely to sentence-parts.

Could we all just drop "state of affairs" and "proposition"? Serious suggestion. Because even the former ends up standing for "sentence". — bongo fury

Ambiguously.

Not that you said "states". Events? Less ambiguous.

Some of the trouble traces back to Alfred Tarski's unfortunate suggestion that the formula " 'Snow is white' is true if and only if snow is white" commits us to a correspondence theory of truth. Actually it leaves us free to adopt any theory (correspondence, coherence, or other) that gives " 'Snow is white' is true" and "snow is white" the same truth-value. — Goodman, Of Mind and Other Matters

and N to be the set of non-linguistic reality bits. — Pie

States, then? States of affairs?

Is this just an issue with use versus mention ? — Pie

"Just"???

Try to correspond with real things or events. Cats, mats and cat-on-mat events. Celebrate your confidence in the correspondence by positing actual entities that are truly called "a cat", "a mat", "a cat-on-mat-event" or are truly related verbally by "is on the".

"The cat's being on the mat" is the controversy. Any such entity?

Sounds a bit straw-manish, admittedly. Can we agree, then?

So. Sentences. Things/events.

Sentences true or false. Things/events corresponding to names or other sentence-parts.

No entities corresponding to whole sentences. No truth-value attaching to things or events that aren't sentences.

I thank you.

Alternatively propositions are expressions, — Michael

Yes please!

in which case the T-schema only applies when something is expressed, — Michael

So, whenever there is a T-schema expression, at least?

Problem?

one of my concerns, truth-makers, which seem like unnecessary entities. — Pie

:up:

Controversial!

"Is truth a property of sentences (which are linguistic entities in some language or other), or is truth a property of propositions (nonlinguistic, abstract and timeless entities)? — Pie

Or is it a property of a state of affairs, whether conceived as a concrete event (region of space-time) or something more abstract? Which latter might be what many people mean by proposition. What a quagmire!

1 truth-bearing sentence/proposition/fact

2 truth-making event/state of affairs/proposition/fact

Not that we have to acknowledge truth-makers corresponding to truth-bearers. Just flagging up the likely misunderstandings coming down the line.

Could we all just drop "state of affairs" and "proposition" and "fact"? Serious suggestion. Because even the first ends up standing for "sentence". At least with those perhaps disavowing correspondence but prone to having it both ways.

There are clear enough reasons to prefer a logic with precisely two truth-values.

But you'd be right that this oughtn't to influence our choice of scaling or classification (of things or values).

Does it though? Colours? Tones? Aren't we multivariate with those?

And your political examples are non-binary too, in a way, as either-or always exchanges for more-or-less. Any fairly entrenched contrast makes way for a spectrum. E.g. either-left-or-right acknowledges how-left-wing?

Maybe what you want is a concept of a spectrum with more than two poles?!

I made it clear I’m not a solipsist (if I was why would I be talking to you?) but I need a logical way to dismiss it. — GLEN willows

Where do you stand on Neurath's boat?

Not too near the edge :lol:

But seriously...

Philosophy once aspired to set all knowledge on a firm foundation. Genuine knowledge claims were to be derived from indubitable truths by means of infallible rules. The terms that make up such truths were held to denote the individuals and kinds that constitute reality, and the rules for combining them into sentences and for deriving some sentences from others were thought to reflect the real order of things.

This philosophical enterprise has foundered. Indubitable truths and infallible rules are not to be had. Philosophy cannot expect to underwrite the assertions of other disciplines, for its own assertions are no more secure than the rest. Nor can it reasonably aspire to certainty. For without indubitable starting points, certainty is beyond our reach. — Catherine Z Elgin

And scientists no longer expect any ultimate foundation or certainty for their theories.

On the other hand... they, and anti-foundationalist philosophers, still seek to systematise, or axiomatise. Not because they expect their theories to derive truth and certainty from their laws or axioms, but the better to evaluate, test, and improve the theories.

Hence @Pie's interest in "fixing the cogito", probably.

But yeah, I suppose if you do accept Descartes' more occult cogito as an indubitable truth, then you are bound to demand a logical demonstration of any claim that a refutation of solipsism is available on that basis.

Let me just start by saying I don't deny private experiences. — Pie

Only if you admit you are admitting defeat.

Haha, this comment is about ten days old. Posted accidentally now. Wrong thread, too. Forgive me. Been enjoying it, but... why cling to the mentalist talk in a "manner of speaking"? Why not be literal? And eliminativist?

I long for death, — Darkneos

Not that you'll ever be in a position to know it.

I have a friend who has no minds eye. She does not see visual mental images. — T Clark

Yes. https://thephilosophyforum.com/discussion/comment/416251

Does she see mental images of the things in front of her?

Sorry but can you dumb that down just a tiny bit? — GLEN willows

"Methodological solipsism" is an oxymoron that fairly makes its own point. In spite of its polysyllables.

Solipsism is an absurd parlour game, or intriguing science fiction; but methodology is science.

But, the two aren't necessarily separate. They can feed each other. Like in any good oxymoron.

REFERENCES. Since the choice of an autopsychological basis amounts merely to an application of the form and method of solipsism, but not to an acknowledgment of its central thesis, we may describe our position as methodological solipsism. This viewpoint has been maintained and expounded in detail, especially by Driesch, as the necessary starting point of epistemology ([Ordnungsl.] esp. 23). I mention here some further adherents of this theory, some of whom apply the solipsistic method only in the initial stages of their systems and eventually make an abrupt jump to the heteropsychological. Since they do not, for the most part, employ any precise forms of construction, it is not always clear whether this transition amounts to a construction on the solipsistic basis, as is the case in our constructional system, or whether it is a desertion of that basis — Rudolf Carnap, The Logical Structure of the World, p102

The title there a provocative oxymoron with metaphysical overtones. (But that's titles for you.) "Aufbau" (I presume "structure") is the usual abbreviation of Der Logische Aufbau Der Welt. I shouldn't have assumed familiarity, especially when I did presume to bandy "umwelt" - I hope correctly.

Anyway, this kind of scientific program does look like an attempt to take the basic empiricist dogma,

Nothing is in the intellect that was not first in the senses — Thomas Aquinas, De veritate, q. 2 a. 3 arg. 19.

literally. But for the sake of theoretical psychology, rather than metaphysical deductions.

Was my point.

Why can't this happen in the dark
— bert1

But as I pointed out, the modelling relation approach to neural information processing says the brain’s aim is to turn the lights out. It targets a level of reality prediction where it’s forward model can cancel the arriving sensory input. — apokrisis

I wonder, am trying to make out, if this answer uses the same lighting metaphor as the question. Because I'm fascinated by the metaphor.

I think the question is, why can't a (super impressive, say mammal-imitating) neural network type machine be a zombie, just like a similarly impressive but old-style symbolic computer/android?

Putting this as a question of whether the world is lit up for the machine in question seems a powerful intuition pump for consciousness. I've found myself spontaneously invoking it when considering discussions of zombies, and of the alleged difference between primary and secondary properties.

Possibly @apokrisis is following that reading, and saying that, paradoxically, consciousness happens as the organism strives to avoid it.

I'm not sure if that would convince the questioner, who might object that it merely describes a kind of attention-management that is easily enough ascribed to a zombie.

But as I say, I'm not sure if that is the intended answer.

As someone who insinuates that the intuition is wrong, even if easily pumped, I of course ought to offer an alternative. Ok, maybe something like, a machine that's one us (one of our self-regarding ilk, properly called conscious) constantly reaches for pictures and sounds that would efficaciously compare and classify the illumination events and sound events that it encounters. It understands the language of pictures, in which black pictures refer to unlit events and colourful ones to lit events. Whereas a zombie, however it deals with what it sees, is like the Chinese room in failing to appreciate the reference of symbols (here pictorial) to actual things.

How is idealism different from solipsism? — GLEN willows

Solipsism is very often in invisible scare quotes, and called methodological - as opposed to metaphysical.

As such it was the method of the earliest efforts in theoretical AI, e.g. Carnap's Aufbau.

Empiricism taken literally. Formal construction of an umwelt from sense data.

So that's one difference. Methodological idealism not a thing.

Dictionary: Phenomenalism, the doctrine that human knowledge is confined to or founded on the realities or appearances presented to the senses. — Art48

Quite possibly presented to, not by.

Just saying.

Then you completely side step the epistemological problem of perception — Michael

Good, if that problem assumes we see and hear internal imagery.

and ignore the actual, substantive disagreement between direct and indirect realists. — Michael

... not "talking past each other", suddenly?

Arguing over the grammatically correct way to talk about perception is meaningless. — Michael

If you mean disputing what elements of folk psychology stand the scrutiny of literal interpretation then I don't see why that should be meaningless. Seems like you're just losing your temper.

Is there a Cartesian theatre [implied] when we say that we feel pain... — Michael

No.

...and that pain is a sensation? — Michael

Yes, if that's in deliberate conjunction with the first. It's obviously setting up a dubious scenario in which a you inside you perceives a representation inside you, instead of just the whole of you perceiving the thing itself, in this case the bodily trauma.

There's no philosophical difference between feeling a sensation and hearing a sensation or seeing a sensation. The nouns simply signify a different modality of perception. — Michael

Yes, they all set up the same dubious scenario, if we aren't careful. They all say, sensing a sensation, or feeling a feeling, seeing a seeing.

It might not be the ordinary way of speaking — Michael

Right, so it's the careful way, that we're meant to take literally?

but that's just an arbitrary fact about the English language — Michael

I'm lost from here on. Again, seems like bluster.

The "language trap" is arguing over which of "I hear the drill" and "I hear the sounds made by the drill" — Michael

Well that hardly needs a hazard warning. I hear, am witness to, the sound event involving the drill. The room, vibrating. Either of the two phrases is innocent glossed as such.

What the event tells us about the drill itself is an interesting question of physics, probably triggering hypotheses about the whole class of sound events involving the same drill.

Further investigation might involve an appropriately defined class of sound events involving loudspeakers, instead of the drill.

(Aesthetic interest may create a fascination with similarly defined classes of events: https://thephilosophyforum.com/discussion/comment/410733.)

The "language trap" is arguing over which of [the above] and "I hear auditory sensations" is correct, — Michael

No, the above are correct, but this version too easily suggests a little loudspeaker in the head, that I'm listening to. Sorry. I know you think that's a straw man, and my misapprehension not yours. Not sure how to get past it.

whereas we should be arguing over whether or not drills have the auditory features that we hear them to have. — Michael

No we shouldn't, we should just clarify whether we are talking about whether they have certain physical features, causing certain kinds of acoustical (sound) event, or about the sound events themselves.

Whether sights or sounds, smells or tastes, it's all just sense data brought about by sensory stimulation and brain activity. — Michael

Or it's all learnt classification of the external stimuli. Types of illumination event, types of sound event, types of chemical diffusion event, types of eating event, types of bodily trauma event (in case you forgot pains).

Words are organic things, and have fuzzy boundaries, and our minds are well constituted to deal with them as such. We happily use the word sandwich, — hypericin

Sure, especially given the inscrutability and all.

never mistakenly using the word with hotdogs. — hypericin

But then how could that ever be a mistake?

Is this a chair problem?

There is no trans-linguistic reality, no platonic essence of sandwiches which you can consult. — hypericin

But neither is there any historical certainty about past usage, or even about uses of a word on particular occasions. (See inscrutability of reference.)

Understanding how language works on such shaky ground is a perfectly chompable problem.

But objects are events.

Our tables, steam yachts, and potatoes are events of comparatively small spatial and large temporal dimensions. The eye of a potato is an event temporally coextensive with the whole, but spatially smaller. The steam-yacht-during-an-hour is an event spatially as large as the yacht but temporally smaller. But the steam-yacht-during-an-hour is an element in a larger whole as is the eye of the potato. — Goodman, Structure of Appearance, 1951

I think the current phrase is "time worm". (Get it?)

See red things. — Michael

No, dreams and hallucinations are us exercising our imagery circuits without succeeding in seeing anything. Illusions covers a multitude, obviously.

We can do that — Michael

Do what?

The point is they don't need language. — Michael

Oh. Well my point is,

And that's how seeing colours is seeing an external material world. It's recognising classes of objects. (Or classes of illumination events.) — bongo fury

A dog can recognise his owner. — Michael

Yes. By learning to compare and classify appearances.

I have no idea what you're talking about. A hermit with no language can recognise when he feels pain. A hermit with no language can recognise when he feels pleasure. A hermit with no language can recognise the difference between feeling pain and feeling pleasure. — Michael

I'm trying my best to make sense of "recognise" without implying language use.

Nothing about this depends on there being some observer who can make, and justify, these claims. — Michael

Agreed.