Not if you include natural language semantics, as far as I can tell. You just also inherit the liars paradox with that.

natural language semantics — Moliere

And what would those be?

The T-schema states:

"p" is T iff p

Using English to provide an interpretation to the schema:

p is any statement in English
" " is the mention operator, where a statement is converted into a name for that same statement.
is T is "... is true", as understood by us as speakers of English.
iff is the familiar logical connective from baby logic.

In general, I'd accept any natural language though. I'm using English because we are. I imagine some natural languages which don't have this structure which this doesn't work for. Also, note, that there isn't some concept securing truth here -- it's really just the history of the predicate "... is true".

The dialogical game I posited with this, when it comes to natural languages, has basically already taken place. There's a few hundred years worth of English usage which gives "... is true" its sense.

This is all I meant by a natural language semantics -- the meaning one gets by understanding a language. If you grant that English sentences have meaning, at least.

If so not... eh... I guess it's just squeeks and squawks all the way down? I'm not really sure there. It's an intriguing notion, but one that doesn't make a lick of sense to me really.

Supposing the search is for an account of what makes any sentence true, holism in some form enters into the discussion from the beginning.

Holism in some form follows if one accepts the Tarski's idea that a theory of truth must generate a sentence of the form "S" is true IFF X for every sentence of the object language.

Davidson's holism links truth, meaning, attitudes, beliefs and the contents of each.

Wittgenstein talks of a form of life, a bringing together of language games, hinge propositions, and common intentions in a just so story.

Yes, it's hand- waving; but so is pointing to where we are going. If you don't know where you're going, any road will take you there.

Quite explicitly, Davidson points out that there are (at least) an infinite number of sentences in English., but only a finite set of words.

We learn the vocabulary and formation rules, and iteratively generate innumerable sentences.

So not

hence the claim that if you understand all the T-sentences of a language, then you understand that language — Srap Tasmaner

but that if you understand how to construct a T-sentences of any sentence in the language, then you understand that language.

Similarly,

if you understand all the T-sentences of a language, do you also understand a world? — Srap Tasmaner

is not the question; it's rather if you can construct a T-sentence for any sentence in the language, what is it that you have not understood?

I think I agree, though I'm slightly unclear on what the first part of your post is saying. (The explanation of T-sentences in English.)

I think there are three possible answers:
(1) Semantics in terms of truth conditions, and no analysis of "is true" is possible because of circularity.
(2) Semantics in terms of truth conditions, and the T-schema is the semantics of "is true". That's it; that's all it can be.
(3) Something besides truth conditions.

Holism in some form follows if one accepts the Tarski's idea that a theory of truth must generate a sentence of the form "S" is true IFF X for every sentence of the object language. — Banno

I'm not following this. I think of holism as indicating that the members of the set are not independent in some respect, in this case truth. Isn't the construction of T-sentences a one-by-one affair?

if you understand how to construct a T-sentences of any sentence in the language, then you understand that language. — Banno

Gotcha. I can never remember quite how he puts this. But this is quite mechanical isn't it? I could construct T-sentences for any collection of sentences of whatever language, whether I understand it or them or not. What am I missing?

The issue, as I see it, is that observational data and evidence should inform our philosophy. When there's a conflict, that's a signal that we need to check our premises. — Andrew M

Yes, I agree.

Allows you to conclude p from Kp, but doesn't tell you whether Kp is true. It is indeed just a logical principle along the lines of modus ponens, which also can't tell you that your premises are true. Does that make modus ponens useless? — Srap Tasmaner

It's not like modus ponens though, because unlike modus ponens, the premises do not necessitate the conclusion. The proposition "I remember that today is Joe's birthday", does not necessitate the conclusion that today is Joe's birthday, without the added premise that my memory is infallible. But that proposition is not stated, nor would it be acceptable as a premise if it was stated. So it's like modus ponens with a hidden premise, which if it were stated, would be rejected as false. Therefore conclusions drawn in this way are unsound.

It seems to me that in the history of ". . .is true" truth conditions are a part of it. But "something else" is too. So 3 to circumvent 1 and allow for creative uses, however for the most part 2.

The proposition "I remember that today is Joe's birthday", does not necessitate the conclusion that today is Joe's birthday, without the added premise that my memory is infallible. — Metaphysician Undercover

Yes it does. No claim that someone's memory is infallible is needed to support the claim that, in this case, it is accurate. Neither does modus ponens require p to be a necessary truth. (Which would just make the exercise pointless.)

In modus ponens, the conclusion follows necessarily from the premises. The conclusion, that today is Joe's birthday does not follow necessarily from the premise "I remember that today is Joe's birthday", because there is no premise to relate "I remember", to what "is".

The conclusion, that today is Joe's birthday does not follow necessarily from the premise "I remember that today is Joe's birthday", because there is no premise to relate "I remember", to what "is" — Metaphysician Undercover

But the connection is right there: the conclusion is the object of the propositional attitude.

You cannot know what is not so. You cannot see what is not there. You cannot remember what did not happen. You cannot regret doing what you did not do.

Every failure you imagine of claims like these are cases where you are simply wrong -- you think it's so but it isn't, you think it's there but it isn't, you think it happened but it didn't, you think you did but you didn't. When you're right, what you are right about is a fact.

My saying that I know, or that you know, or that someone else knows, is of course no guarantee. So what? Logic doesn't guarantee the truth of what you say, but connects one truth to another.

That's all we're doing here. There's nothing particularly subtle about it.

I lean toward (2), but I just don't know enough to say.

I keep thinking there's something of interest there in truth as a sort of identity function. Have you noticed that it works for anything you might count as a truth-value? It works for "unknown," it works for "likely" or "probably," even for numerical probabilities. Whatever you plug in for the truth-value of p, that's the truth-value of p is true. If you think of logic as a sort of algebra, that makes the is-true operator (rather than predicate) kind of interesting.

I'm not clear where this is going. I don't think there's anything about saying that "the kettle" is defined functionally which renders it victim to Oliver's dad's joke position.

If I say "Pass me the kettle", I'm just using an expression which I've learned is a tool to get something done. In my terminology, I have an expectation that the world be such that I can fill something with water and I'm interacting with the world via language to make it match my expectation. It's a prediction of what action will make it that way. As Wittgenstein has it at the beginning of the PI, I could have just said "kettle!", or simply pointed to it and clicked my fingers.

Nothing here defines what "the Kettle" means in any specific way. It's a tool I reach for as part of a strategy to get some change in the world enacted, and it's non-specific. So long as it gets the job done. It's sufficient, it seems to keep these expressions vague, relying on compound ones to be more specific "that kettle over there, the red on, not the black one..."

The point of all this was to say that there's no eternal, external, definition of what constitutes "the kettle" that anyone could use to determine the truth (by correspondence) of "'the kettle is black' is true". There's no corresponding external world object to "the kettle"

"The kettle" is a linguistic act. Saying that something corresponded to it would be like saying that something corresponds to my extended finger when I'm pointing at the kettle. If I point and say "pass me the kettle", nothing different has happened than if I point and click my fingers, motion with my had that you're to pass me the object I'm pointing to. But we don't say that my action with my hands 'corresponds' to the object in question, so why should my actions with my voice box do so?

With the pointing and gesturing, I rely on the fact that you share sufficient aspects of my expectations, and that my goals are sufficiently part of yours, that you'll see my actions as evidence for your policies. The same seems the case with language acts.

Bring this back to 'Truth', the notion that "X is true" can be checked by examining the properties of X relies on 'X' referring to some fixed set of properties. But 'X' doesn't refer to a fixed set of properties. 'X' doesn't refer at all, it's a type of action that gets a job done, it doesn't refer any more than lifting my arm does.

I think where we differ is that I interpret the pragmatic context as part of the function, and the function itself isn't situated within a body, it's situated between bodies, in the environment, and within bodies - like with Srap Tasmaner 's comment about externalism vs internalism of semantic content. I don't think "the science" sides with either side on that, at least not yet, so it remains a site of substantive philosophical disagreement. — fdrake

As I said above to Srap, The idea that I can change the external world by some vocalisation (same for doing so by some gesture) to others does indeed rely on the notion that those other sufficiently share my models, and that co-operation is sufficiently part of their policy, for those gestures to work. But I don't agree that it requires a set of shared 'meanings' which are then reified to some objective status with sufficient specificity to be amenable to truth analysis. We can invent gestures on the hoof and still be understood. If there's a language barrier, certain words are quickly learned (and what is learned, is what the word does). Communicating with someone who doesn't share my language is less efficient, but still very possible and we can carry out many basic co-operative tasks, we don't seem to need an already prepared external system of word and reference.

So I think, yes, this is all about our shared would, but I don't think the co-operation this is all here to allow requires an actual set of word>reference facts that are external to our intentions. It simply requires that we're similar enough in intentions and co-operative enough in policy that we can see evidence, in another's behaviour, of what we need to do to bring about the state of the world which includes helping the other.

I lean toward (2), but I just don't know enough to say. — Srap Tasmaner

Eh, I'm just feeling around here too. One thing I'm leery of with (2) is that I've been saying I assume meaning -- so really I'm asking my interlocutor if they agree that we understand English sentences. Insofar that we agree upon that then the rest follows. But if you ask me to specify a semantics, then I can no longer specify truth. Here we'd be taking the tactic of assuming truth to spell out meaning.

But I think I'm still thinking (3) since I'm assuming meaning to spell out truth with English. (2) because of the actual history of semantics, though, has weight. And starting at something so specific as the English predicate ". . . is true" is much more at my level of being able to conceptualize. (L1? L2? What? :D)

I keep thinking there's something of interest there in truth as a sort of identity function. Have you noticed that it works for anything you might count as a truth-value? It works for "unknown," it works for "likely" or "probably," even for numerical probabilities. Whatever you plug in for the truth-value of p, that's the truth-value of p is true. If you think of logic as a sort of algebra, that makes the is-true operator (rather than predicate) kind of interesting.

Hah, no I had not noticed. I think what keeps what I've been trying to say from collapsing into an algebra, where is-true is an operator on propositions, is the actual history. I like the relationship that's spelled out by the T-sentence which shows how truth is embedded within used language. When using a statement -- that's what has a truth-value. That's what's truth-apt. When naming a statement, that's what we assign truth-value. It's a judgment. But the used statement is what counts as the truth-apt statement.

I don't agree that it requires a set of shared 'meanings' which are then reified to some objective status with sufficient specificity to be amenable to truth analysis. We can invent gestures on the hoof and still be understood. If there's a language barrier, certain words are quickly learned (and what is learned, is what the word does). — Isaac

Bring this back to 'Truth', the notion that "X is true" can be checked by examining the properties of X relies on 'X' referring to some fixed set of properties. But 'X' doesn't refer to a fixed set of properties. — Isaac

Is this typically what the word "truth" (or "is true") does?

'X' doesn't refer at all, it's a type of action that gets a job done, it doesn't refer any more than lifting my arm does. — Isaac

I thought we were discussing what "is true" does, not what "X" (or "the kettle" or "the kettle is boiling") does.

(2) Semantics in terms of truth conditions, and the T-schema is the semantics of "is true". That's it; that's all it can be. — Srap Tasmaner

I lean toward (2), but I just don't know enough to say. — Srap Tasmaner

I find the part in bold problematic. Is "p" is foo iff p the semantics of "is foo"?

As I said at the start of this discussion, I think a distinction needs to be made between these two claims:

a. "p" is true iff p
b. "'p' is true" means "p"

I would say that (b) would count as an explanation of the semantics of "is true" but that (a) doesn't.

A proposition p is true only if p doesn't entail a contradiction. Conversely, if a proposition p entails a contradiction, p is false. We can only know what is false; truth, on this view, is indeterminable. Falsifiability/testability (re Karl Popper). :chin:

You cannot know what is not so. You cannot see what is not there. You cannot remember what did not happen. You cannot regret doing what you did not do. — Srap Tasmaner

All of these examples, "know", "see", "remember", and "regret", require another premise establishing a relationship between each one of them, and "what is", in order to produce a valid conclusion.

There is no premise which states that if you "know" it, it is. No premise which states that if you "see" it, it is, nor for "remember", or "regret".

I could just as easily say, "if I feel like it's going to rain this afternoon, then it is going to rain", or, "intuition tells me so". What makes "regret", "remember", "see", or "know" produce a more valid conclusion than "feel" or "intuit"? Or, we could take the example from . If I say "pass me the kettle" does this imply that there actually is a kettle? Validity requirements do not allow us to make such conclusions. That's why a definition of sorts is a required part of the premises.

Logic doesn't guarantee the truth of what you say, but connects one truth to another. — Srap Tasmaner

Logic guarantees that properly derived conclusions are valid. Your conclusions for the attitudinal propositions are not valid, because they depend on unstated definitions for terms like "know", "see", etc.. Valid logic uses premises which state something necessary, or essential about a term ('man is mortal' for example), and then it proceeds to utilize that necessity stated, to produce a valid conclusion.

You have not stated the necessary premises concerning the terms, "know", "see", etc;, to produce a valid conclusion. And, if you did state those premises, "if you know it then it is true", "if you see it then it is true", they would just be rejected as false propositions. So it's as if you believe that by not stating the required premises you can avoid having them rejected as false, and simply proceed to produce a valid conclusion without the required premises through some sort of sophistry. But you cannot, because the premises are required to produce a valid conclusion.

if you did state those premises, "if you know it then it is true" — Metaphysician Undercover

You mean if I wrote something like this?

$\ \ \ \ \ Kp\ \vdash\ p$

Like stating that kind of premise? Or would you prefer something like this?

$\ \ \ \ \ \forall p(\exists x Kxp\ \to\ p)$

But then, honestly, I'm not sure what there is to talk about if your position is that one can know things that are not so, see things that are not there, remember things that did not happen, and regret doing things you did not do.

I'll let you have the last word.

Is "p" is foo iff p the semantics of "is foo"? — Michael

You just read the Tarski, right? I haven't done that in years, so you're better placed than I.

I think, yes, that is the semantics of "is foo." It says, in plain English, that whatever the truth conditions of p are, those are the truth conditions of 'p' is foo, and vice versa. And it's also obvious that any such predicate "is foo" is equivalent to "is true," that there is a unique identity function on truth-values, and thus a unique identity function on truth conditions.

Honestly, though, I'm out of my depth here. I know little formal semantics.

I think, yes, that is the semantics of "is foo." It says, in plain English, that whatever the truth conditions of p are, those are the truth conditions of 'p' is foo, and vice versa. And it's also obvious that any such predicate "is foo" is equivalent to "is true," that there is a unique identity function on truth-values, and thus a unique identity function on truth conditions. — Srap Tasmaner

So you're saying that these are equivalent?

1. "p" is true iff p
2. "'p' is true" means "p"

Tarski's T-schema is Ramsey's redundancy theory?

And it's also obvious that any such predicate "is foo" is equivalent to "is true," that there is a unique identity function on truth-values, and thus a unique identity function on truth conditions. — Srap Tasmaner

I'm not sure about this. Are these equivalent?

1. "p" is true iff p
2. "p" is a true sentence iff p
3. "p" is a sentence iff p

(1) might be equivalent to (2), but neither (1) nor (2) are equivalent to (3), and (3) follows from (2).

So does "is foo" mean "is true" or "is a true sentence" or "is a sentence" or something else?

So you're saying that these are equivalent?

1. "p" is true iff p
2. "'p' is true" means "p" — Michael

If you take take means as has the same extension as, then yes. Otherwise, no, or depends.

Are these equivalent?

1. "p" is true iff p
2. "p" is a true sentence iff p
3. "p" is a sentence iff p — Michael

They can't all be true at the same time, because the use of "sentence" in (2) conflicts with its use in (3), doesn't it?

My point was that any function that assigns to every sentence the same truth-value it has already, is equivalent to what we've been writing as "is true," and there can only be one such function. Am I missing something?

They can't all be true at the same time, because the use of "sentence" in (2) conflicts with its use in (3), doesn't it? — Srap Tasmaner

Yes, good point. Not sure what I was thinking there. Obviously (3) is false.

If you take take means as has the same extension as, then yes. Otherwise, no, or depends. — Srap Tasmaner

So "p" and "'p' is true" have the same extension but might have a different intension?

I suppose the same could be said of "'p' is true" and "'p' is foo", and so of "is true" and "is foo". Same extension, possibly different intension?

I think a definition of "is true" (and "is foo") should explain its intension.

So "p" and "'p' is true" have the same extension but might have a different intension? — Michael

Well, something like that has always been the complaint about purely extensional semantics. From "The Meaning of 'Meaning'," which just happens to be on another tab in my browser:

the timeworn example of the two terms "creature with a kidney" and "creature with a heart" does show that two terms can have the same extension and yet differ in intension.

Conversely, if a proposition p entails a contradiction, p is false. We can only know what is false; truth, on this view, is indeterminable. — Agent Smith

If we know that p is false then we know that not-p is true.

If we know that p is false then we know that not-p is true. — Michael

:blush: Missed that ... in my haste. However ... if p is known to be false, ~p is true isn't enough in all cases. For example if the theory of relativity is falsified (proven false via some hypothetical observation), what exactly is not Theory of Relativity? :chin:

That said, In the case of propositions like god exists, knowing that it is false indeed means the contradictory, god doesn't exist is true.

So we now have a method of determining truth, oui monsieur?

For any proposition p, assume p and check if it entails a contradiction. If it does, p is false i.e. ~p is true. Interesting to say the least.

We now have a definition of what true means: if ~p entails a contradiction, p is true.

Muchas gracias. is there anything else you wanna add to this?