It's raining outside is true if and only if it's raining outside. — Marchesk

... is incorrect. The syntax is muddled.

What is it about the RHS that makes the LHS true? — Marchesk

Why do you think the right hand side makes the left hand side true? That strikes me as an odd notion. An animal has a heart if and only if it has kidneys; therefor the kidneys make it true that the animal has a heart? Jim likes chocolate if and only if it does not contain nuts; therefore not containing nuts makes Jim like chocolate?

This makes no sense.

In direct speech: "It's raining outside" is true If and only if it is raining outside.

In indirect speech: That It is raining outside is true If and only if it is raining outside. The subordinate clause "It is raining outside" is governed by the verb "is".

But your

It's raining outside is true if and only if it's raining outside. — Marchesk

is just ill-formed.

The cat on the mat is true if and only if the cat is on the mat. — Marchesk

You're goofing the syntax.

"The cat is on the mat" is true iff the cat is on the mat.

Deflationists don't argue that there's a correspondence relation that maps propositions to states of affairs. Truth, in other words, is not taken to be a substantive property that a proposition had. Rather (again, depending on the account) will mean that truth is really all and only about the linguistic conventions governing the predicate "is true".

The mistake you're making is thinking that the T-scheme (<p> is true iff p) assumes correspondence. It doesn't, that's just a nice heuristic to get one to understand the schema but it's not actually assumed in the schema. Many philosophers who aren't correspondence theorists still accept instances of the schema.

Why do you think the right hand side makes the left hand side true? That strikes me as an odd notion. — Banno

Really? Despite the T-schema and the disquotation?

The cat is on the mat.

By itself, this is neither true nor false. Is true adds something to the sentence. It's saying two things:

1. The sentence is not false.
2. There is an actual cat on an actual mat being referred to.

#2 is why the sentence is true and not false. Without that, you have a meaningless assertion. There is no necessity to cats being on mats, so it's not a necessary truth, or true by definition.

As such, the RHS (the disquoted side) is what makes the sentence true or false.

Rather (again, depending on the account) will mean that truth is really all and only about the linguistic conventions governing the predicate "is true". — MindForged

And that's a totally trivial observation that nobody ever disagreed with. Of course we have a linguistic agreement on how truth and false are to be used.

Pilate: "What is truth?"

Jesus: "A linguistic convention governing the predicate 'is true'."

Pilate: "So everyone who heareth the truth is just agreeing that 'is true' is a linquistic convention? Well alrighty then, there's nothing controversial in what you're saying. Let me have a talk with the Jewish leaders. Those silly goats. They thought you were claiming to be a god or something, but you were just taking about language games the whole time."

And that's a totally trivial observation that nobody ever disagreed with. — Marchesk

Are you serious? I just said that on the deflationists account there is *nothing* more to truth than the conventions that govern it's usage as a predicate. Literally every other theory of truth denies this, especially correspondence since truth is not simply a predicate with use-conventions. It articulates the instantiation of a relationship (correspondence) between do two ontologically distinct kinds of things (sentences/propositions and facts) thus yielding the substantive property of truth as held by the proposition.

Again, the T-scheme does not make reference to facts or correspondence with the use of p.

1) <p> is true
2) if and only if
3) p

Hence it's perfectly compatible with non-correspondence theories like deflationism.

From the IEP:

To capture what he considered to be the essence of the Correspondence Theory, Alfred Tarski created his Semantic Theory of Truth. In Tarski's theory, however, talk of correspondence and of facts is eliminated. (Although in early versions of his theory, Tarski did use the term "correspondence" in trying to explain his theory, he later regretted having done so, and *dropped the term altogether since it plays no role within his theory*.) The Semantic Theory is the successor to the Correspondence Theory. It seeks to preserve the core concept of that earlier theory but without the problematic conceptual baggage.
[...]
We can rewrite Tarski's T-condition on three lines:

The proposition expressed by the German sentence

1) "Schnee ist weiss" is true
2) if and only if
3) snow is white

Line 1 is about truth. Line 3 is not about truth – it asserts a claim about the nature of the world. Thus T makes a substantive claim. Moreover, it avoids the main problems of the earlier Correspondence Theories in that the terms "fact" and "correspondence" play no role whatever.

Are you serious? I just said that on the deflationists account there is *nothing* more to truth than the conventions that govern it's usage as a predicate. — MindForged

Okay, I mean nobody disagrees with saying that true and false are linguistic conventions we agreed to. That's not what's of importance. We could have used any word to denote the meaning behind true and false. And it's the meaning that's at stake.

What the defalationist is saying amounts to there being no meaning other than the lingustic convention, which sounds prima facia absurd, and what I'm trying to argue against.

1) <p> is true
2) if and only if
3) p — MindForged

Right, but this is merely a rule in logic and says nothing about how we apply assertions to the world or other domains.

The cat is on the mat isn't merely a logical proposition. It's a statement about the world. It's only true if there is an actual cat on the actual mat being talked about. Otherwise, it's either false or meaningless (if not referring to any cat/mat).

1) "Schnee ist weiss" is true
2) if and only if
3) snow is white

Line 1 is about truth. Line 3 is not about truth – it asserts a claim about the nature of the world. Thus T makes a substantive claim. Moreover, it avoids the main problems of the earlier Correspondence Theories in that the terms "fact" and "correspondence" play no role whatever.

This is better. The problem is that Line 3 is what makes line 1 true. Explaining how that is the case is where correspondence and the other theories of truth come in.

So I'm not sure what the deflationist is trying to say here. Are they denying anything else needs to be said about the relationship between Line 3 and Line 1? Because questions about how we know that the snow is white are going to rear their head at this point.

Consider we're inside and the weather report says it's snowing out side. So I say,

"The snow is white".

You go out and look and say: "Nope, it's actually yellow."

And I"m like, "Bro, snow is white, stop lying!"

But then I go and look and I see that it is yellow, because you took the chance to unburden your bladder there.

Because questions about how we know that the snow is white are going to rear their head at this point.

Consider we're inside and the weather report says it's snowing out side. So I say,

"The snow is white".

You go out and look and say: "Nope, it's actually yellow."

And I"m like, "Bro, snow is white, stop lying!"

But then I go and look and I see that it is yellow, because you took the chance to unburden your bladder there. — Marchesk

So that is a question of what is meant by "snow is white". If you are talking about the reflective properties of snow, that is one meaning. If your friend is talking about the color of some particular patch of snow, that is another meaning. One may be conventional, another idiosyncratic. Or both may be conventional meanings, depending on context. The truth schema allows you to choose whichever meaning you like based on your metaphysical or pragmatic preferences. Which is to say, it's not an issue about truth.

As such, the RHS (the disquoted side) is what makes the sentence true or false. — Marchesk

What's the point of my replying to you if you do not address my writing?

Why do you think the right hand side makes the left hand side true? That strikes me as an odd notion. An animal has a heart if and only if it has kidneys; therefor the kidneys make it true that the animal has a heart? Jim likes chocolate if and only if it does not contain nuts; therefore not containing nuts makes Jim like chocolate? — Banno

What's the point of my reyplying to you if you do not address my writing? — Banno

I did address your writing, just not the kidney part, because it's irrelevant since kidneys are not hearts.

My friend, there simply is not a causal link between the right side and the left side of the material equivalence.

My temptation now is to walk away from this thread. I'm doubting that we share an understanding of the logic involved.

Okay, I mean nobody disagrees with saying that true and false are linguistic conventions we agreed to. That's not what's of importance. We could have used any word to denote the meaning behind true and false. And it's the meaning that's at stake.

What the defalationist is saying amounts to there being no meaning other than the lingustic convention, which sounds prima facia absurd, and what I'm trying to argue against. — Marchesk

My initial post was responding to the part of the OP which suggested that deflationary theory, prima facie is just correspondence theory. That's why I pointed out the crucial difference, namely eliminating the use and roles of "fact", correspondence and the like.

So I'm not sure what the deflationist is trying to say here. Are they denying anything else needs to be said about the relationship between Line 3 and Line 1?

One may well say Correspondence is a sufficient but not necessary condition while still be a deflationary theorist, I suppose. To quote from Leeds:

It is not surprising that we should have use for a predicate P with the property that “‘_ _ _ _ _’ is P” an d “_____” are always interdeducible. F or we frequently fin d ourselves in a position to assert each sentence in a certain infinite set z (e.g. w hen all the members of z 11 O n the preceding page Soames makes clear that he takes Tarski to be com mitted both to sufficiency an d to necessity. T he point here is that the “must” obscures the fact that the claims about partial definition can support only the claim that implication of the biconditionals is sufficient.Theories of Truth and Convention T share a common form); lacking the means to formulate infinite conjunctions, we find it convenient to have a single sentence which is warranted precisely when each member of z is warranted. A predicate P with the property described allows us to construct such a sentence: (x)(x ∈ z → P(x)). Truth is thus a notion that we might reasonably want to have on hand, for expressing semantic ascent an d descent, infinite conjunction and disjunction. And given that we want such a notion, it is not difficult to ex plain h o w it is that we have been able to invent one: the Tarski sentences, which axiomatize the notion of truth, are by no means a complicated or recondite axiomatization; the possibility of moving from this axiomatization to the explicit truth definition was always latent in the logical structure of language, though it took a Tarski to discover it. Truth is useful, we may say, as a device of (what Quine calls) disquotation … . To explain the utility of disquotation we need say nothing about the relations between language and the world.

WRT the T-scheme, the right side of the biconditional does not make the other side true, they re logically equivalent. So:

<Snow is white> is true if and only if snow is white

Does not mean "snow is white" is made true because of the whiteness of snow. It means '<Snow is white> is true' has the same truth value as 'snow is white', because each implies the other.

My friend, there simply is not a causal link between the right side and the left side of the material equivalence. — Banno

Oh, I see what you're saying with those analogies. But if there is not a causal link, then how is the right side related to the left?

'<Snow is white> is true' has the same truth value as 'snow is white', because each implies the other. — MindForged

Alright, but that's false, because snow is not always white, just like the cat is not always on the mat. You need something else to make the two equivalent.

how is the right side related to the left? — Marchesk

Well, each side will be true if and only if the other side is also true.

What are you asking?

The truth schema allows you to choose whichever meaning you like based on your metaphysical or pragmatic preferences. Which is to say, it's not an issue about truth. — Andrew M

What is truth?

Can be restated as:

Wha is it that makes a statement true, such that the cat is on the mat is not false or meaningless?

I'm failing to see how deflation addresses that question.

Alright, but that's false, because snow is not always white, just like the cat is not always on the mat. You need something else to make the two equivalent. — Marchesk

You do understand that:

"Snow is white" is true only if snow is white

is true even if snow is polkadot?

Alright, but that's false, because snow is not always white, just like the cat is not always on the mat. You need something else to make the two equivalent. — Marchesk

Ok, I think I'm about to agree with Banno that you either don't understand the logic or there's some communication issue. Because it doesn't matter. Pick whatever well-formed, true sentence you want (ignoring Liar sentences). Append the predicate "is true". Those will have the same truth value, as per the T-scheme. But the T-scheme makes no comment about what truth is, so deflationary theories aren't sneaking in a correspondence theory of truth (well, maybe some are but it's not a necessary features of simply accepting the T-scheme).

Perhaps I'm missing something. My understanding is that deflation is an attempt to avoid problems that crop up with other theories of truth, because they have metaphysical implications. To avoid that, deflation is proposing an identity between making a statement and that statement being true.

It seems obvious to me this runs into a serious problem because statements can also be false, so merely stating that the cat is on the mat is not the same thing as saying the cat is on the mat is true.

Consider:

The cat is on the mat is false.

The cat is on the mat is true.

Now the question arises as to what makes the cat on the mat true or false. Am I misunderstanding in thinking that deflation needs to address this? The debate about the nature of truth seems to concern itself with what makes statements true, right?

The cat is on the mat" is true iff the cat is on the mat.

If that has any meaning beyond syntax, then the obvious thing to point out is that there is at minimum an empirical cat on an empirical mat that makes that T-schema work. Otherwise, it's a meaningless logical statement that has nothing to do with cats or mats.

The blorg is in the korg is true iff the blorg is in the korg.

Is that all deflation is saying? Because that's not saying anything other than pointing out a rule of logic. It certainly not concerning itself with what the other theories of truth are worried about.

is true even if snow is polkadot? — Banno

No, I don't understand that at all. You just said the snow is white in the T-schema.

X is true iff x is true.

Is that all we've been arguing about? Because that tells me nothing that I didn't already know. Of course a statement is true if and only if it's true.

Yeah, you don't understand how the T-schema works.

That explains this thread.

Cheers.

To avoid that, deflation is proposing an identity between making a statement and that statement being true. — Marchesk

I don't think that's quite right. It's not an identity, it's an equivalence. The T-scheme is a biconditional, so the deflationist (if, as usual, they accept that schema) they are simply accepting that when snow is white, the rules governing the truth predicate allows me to say it's true that snow is white. Similarly, if snow were not white (i.e. "snow is white" is false) then the linguistic conventions governing the falsity predicate allows me to use it there. (Thinking prosentential deflationism, performative deflationism)

Under Correspondence theory, it's the correspondence relation that maps the proposition onto the fact, making the proposition true. But that's not the T-scheme because

<p> is true iff p (T(p) <=>p)

Isn't saying 'p' makes 'p is true' the case. It just means they have the same truth value. Neither is "deeper" than the other, they're equivalent. It's the same as (P->Q) ^ (Q->P), they yield each other in all models.

Whatever truth means, it is not given to us by the T-scheme because, if you read it, the T-scheme uses truth in its biconditional. It just tells me how I can use the predicate.

That explains this thread. — Banno

Then explain it. Because I see no reason to accept deflation based on what's been stated so far.

Whatever truth means, it is not given to us by the T-scheme because, if you read it, the T-scheme uses truth in its biconditional. It just tells me how I can use the predicate. — MindForged

Okay, so it then has nothing to do with the question of what truth is?

"Snow is white" is true only if snow is white

is true even if snow is polkadot? — Banno

It's true in a totally trivial manner. Seems to be expressing an identity, except that the first one is quoted.

What that has to do with actual snow being white or cats being on mats is beyond me. Because the cat is on the mat expresses nothing unless it's referring to a cat on the mat, which could be true or false depending on whether the actual cat is on an actual mat being referred to.

X is true iff x is true.

Is that all we've been arguing about? Because that tells me nothing that I didn't already know. Of course a statement is true if and only if it's true — Marchesk

That formulation isn't the T-scheme and it explains nothing. What I'm saying is this. The T-scheme has nothing to do with the Correspondence Theory of truth, not by necessity anyway.

Okay, so it then has nothing to do with the question of what truth is? — Marchesk

I wouldn't say nothing. Not only does it tell us how to use the predicate, according to Tarski any viable theory of truth must satisfy this convention where all the true sentences have a logically equivalent sentence (one with the same truth-value) with the "is true" predicate.

It's intended to be a necessary feature of a good truth theory, basically. That's why it's unclear if you ought to characterize Tarski's theory of truth as deflationary or correspondence, because the T-scheme works for both.