If you already believe the statement, then adding "is true" adds nothing meaningful to it. — creativesoul

But I don't believe that there is life on Mars or that Julius Caesar had that number of hairs on his head. I don't disbelieve it either, because I just don't know, although my number is unlikely to be the correct one.

Problems will certainly arise from conflating verification with truth. — creativesoul

Right because a BIV can verify that a cat is on the mat, while wrongly believing this means there is an external world cat on a mat. And that's essentially what the ancient skeptics were saying. That we couldn't know whether our statements were true.

If you already believe the statement, then adding "is true" adds nothing meaningful to it.
— creativesoul

But I don't believe that there is life on Mars or that Julius Caesar had that number of hairs on his head. I don't disbelieve it either, because I just don't know, although my number is unlikely to be the correct one. — Marchesk

So you do not believe them. Is that a problem aside from irrelevancy? The conversation is about belief statements.

Problems will certainly arise from conflating verification with truth.
— creativesoul

Right because a BIV can verify that a cat is on the mat, while wrongly believing this means there is an external world cat on a mat. — Marchesk

You lost me here...

You lost me here.. — creativesoul

The BIV can verify their statement that a cat is on the mat, but the statement is false, provided that the BIV thinks the cat is an external object and not just a sensory impression. A BIV never perceives a real cat.

However, it's interesting to note that if a BIV is an idealist, their statement is true.

However, it's interesting to note that if a BIV is an idealist, their statement is true. — Marchesk

That doesn't quite seem right as the BIV hypothesis is consistent with physicalism. Their experiences might be manufactured but they're still physical (i.e. brain states or whatever). So perhaps you meant to say that if the BIV is an anti-realist then their statement is true?

So perhaps you meant to say that if the BIV is an anti-realist then their statement is true? — Michael

Sure. As long as "The cat is on the mat" is understood to mean my perception (or experience) of a cat on a mat, and not of a cat independent of perception.

What's interesting here is that the meaning a speaker intends for a statement can effect it's truth conditions.

As such, we can't really determine whether a BIV is right or wrong in saying that the cat is on the mat without knowing what they mean. What if they somehow realized or became convinced they were envatted? Then the cat on the mat means electrical stimulation of their visual cortex, or code in a computer program, which is certainly very far form the ordinary understanding of a cat being on a mat.

The solipsist and I can agree that the cat is on the mat. It's true for both of us. But the solipsist means something different than I do, because I take cats to have their own existence independent of me, with their own feline mental states.

"The cat is on the mat" solipsist version is different from "The cat is on the mat" realist version. What makes the solipsist version true is simply the appearance of a cat on the mat. What makes the realist version true is whether the real cat is actually on the mat, despite appearances.

It's true that normally we don't have reasons to doubt the appearance of a cat on a mat, but it's possible under certain scenarios. Those scenarios won't make any difference to the solipsist. It's all just appearance in their mind.

Is true performs a different role for the same sentence, depending on one's metaphysical commitments.

Your last few posts seem misguided. You argue as if truth is existentially dependent upon language. It's most certainly not. While I would readily agree that the truth of belief statements most certainly is, not all belief is equivalent to a belief statement. Non-linguistic belief can be true/false. If true belief is not existentially dependent upon language, than neither is truth, lest the result is incoherence, self-contradiction, and/or nonsense.


Solipsism is a thought experiment. It is a metacognitive endeavor. It is thinking about one's own thought and belief(metacognition). Metacognition is existentially dependent upon written language. It only follows that solipsism is existentially dependent upon written language. Written language is existentially dependent upon shared meaning. Solipsism is existentially dependent upon shared meaning. Shared meaning is existentially contingent upon a plurality of minds. Solipsism is existentially dependent upon a plurality of minds. Solipsism is a fool's game based upon a gross misunderstanding of thought and belief and how they work.

BIV is the same kind of endeavor working fro the same gross misunderstanding.

Because it entails the correspondence theory of truth, which is a metaphysical understanding of truth that deflationism is trying to avoid. — Marchesk

As I said in my previous comment, the correspondence account of truth is not a metaphysical theory. This is in keeping with Kantian philosophy (even Heidegger acknowledges the provenance of the correspondence account). It is also the logic inherent in Tarski's formulation. I'm not sure what you're looking for beyond that.

Right, there isn't, as long as one isn't doing philosophy and is only speaking in ordinary terms. But at least as far back as the ancient philosophy, problems arose for our naive view of things such as truth just being a matter of checking to see whether the cat is on the mat. Why is that? Well, because of things like skepticism, relativism, and the problem of perception. — Marchesk

They aren't problems for truth though. If the referred context of a claim such as "Earth is the third planet from the sun" is our shared experience (which is generally the case in ordinary use), then it is true independently of skeptical claims about BIVs and the like. That undermines skepticism and the problem of perception. It can also be seen that relativism just involves an idiosyncratic use of "true".

A truth schema is an abstraction that allows you to plug in whatever claims you like but the schema itself doesn't itself depend on any specific metaphysical claims.

I get what the deflationist is trying to do, but it seems to me like it does so by ignoring what motivated the whole truth debate in the first place. — Marchesk

Maybe. But it can also make it easier to identify what the problems are (and whether they are substantial).

According to the deflationary theory of truth, nothing is added to the assertion, "The cat is on the mat.", by saying the "The cat is on the mat is true.", since to assert it is to say it's true. — Marchesk

Well, sort of.

The deflationary theory holds that truth is not a predicate. It marks out a role for truth that is distinct from predication, in much the same way that "Existence is not a predicate" marks out a special role for existential quantifiers in predicate logic.

And that has a great deal of intuitive appeal. After all, if it is a predicate, what does it predicate?

Simplest version:
"P" is true IFF P

"The cat is on the mat" is true only if the cat is on the mat.

Now given the conditional, I do not see how the objection in your second paragraph can be properly parsed...

However, the cat might not be on the mat, and thus the assertion could be false. What makes the statement true or false? Whether the cat being referred to is actually on a mat. And that's a situation in the world, which we might call a state of affairs or fact of the matter. It is the world which makes statements about the world true or false. But this is the correspondence theory of truth. — Marchesk

...because if the cat is not on the mat, then "The cat is on the mat" will be false, and

"The cat is on the mat" is true only if the cat is on the mat.

will still be true.

It looks like a non-starter.

.because if the cat is not on the mat, then "The cat is on the mat" will be false, and

"The cat is on the mat" is true only if the cat is on the mat.

will still be true.

It looks like a non-starter. — Banno

Yes, but the interesting thing about truth, and the reason it became a question, was in what makes a statement true or false.

Sure, we can all go look and see the cat is on the mat, and agree that's true, in an everyday sense. But that whole distinction between appearance and reality, where maybe sometimes it only looks like the cat is on the mat, resulted in serious questions about knowledge and truth, a long time ago.

That just don’t work.

That just don’t work. — Banno

Is true or false?

Yes, but the interesting thing about truth, and the reason it became a question, was in what makes a statement true or false. — Marchesk

What makes "the cat is on the mat" true is that the cat is on the mat. The End.

You might have in mind one of these correspondence objections. If so, let me know.

I think your issue is that although we can accept the truism that "the cat is on the mat" is true iff the cat is on the mat, this doesn't actually say anything substantive, and the significant statement that needs completing is "the cat is on the mat iff ...".

Is the cat on the mat iff a particular bunch of atoms are arranged a certain way (i.e. physicalism)? Is the cat on the mat iff a particular set of qualia occurs (i.e. idealism)? These are the sorts of metaphysical answers that the deflationary theory of truth doesn't attempt to provide, but these seem to be the sort of answers that you're looking for.

These are the sorts of metaphysical answers that the deflationary theory of truth doesn't attempt to provide, but these seem to be the sort of answers that you're looking for. — Michael

Right, so what is the deflationist trying to say? The cat is on the mat iff ... what, exactly?

What makes "the cat is on the mat" true is that the cat is on the mat. The End. — Banno

Right, but what does that mean? And of course, on a common sense reading, it's just looking and seeing that the cat is on the mat. But that's just the start of the matter, because philosophy isn't simply espousing common sense.

Right, so what is the deflationist trying to say? The cat is on the mat iff ... what, exactly? — Marchesk

They're not answering that question.

They're not answering that question. — Michael

Yeah, but it seems to me they need to. Otherwise, deflation is stating a truism.

And of course, on a common sense reading, it's just looking and seeing that the cat is on the mat. — Marchesk

You said this earlier as well but it's not correct. "p" is true iff p is an expression of how the word "true" is used. On that usage, a claim can be true even if no-one looks.

Similarly for Aristotle's definition of truth - it does not mention verification.

But that's just the start of the matter, because philosophy isn't simply espousing common sense. — Marchesk

Right. Philosophy is an inquiry that starts with observation, not common sense.

They're not answering that question.
— Michael

Yeah, but it seems to me they need to. Otherwise, deflation is stating a truism. — Marchesk

"p" is true iff p is a formal rule that is derived from observing how people ordinarily use the word "true". Whether or not it does capture that use is an empirical question (which can be investigated).

Sure, but "what does that mean?" and "Is that true?" are at least prima facie not the same; Davidson put a fair amount of effort into trying to show otherwise, and still the discussion goes on.

Otherwise, deflation is stating a truism — Marchesk

Well, that's rather the point. Saying that "P" and saying that "'P' is true" amount tho the very same thing.

Deflation is a response to the various inflationary theories: pragmatism, coherence, correspondence and so on, that try to analyse the property truth. Deflation, as I pointed out before, denies that truth is a property.

But I remain unsure of exactly what your objection is. Back to:

It is the world which makes statements about the world true or false. — Marchesk

Ok, so what is it in the world that makes "the bishop always stays on the same colour square" true? What in the world makes "twice two is four" true? What make "I am Banno" true?

This to show that correspondence, despite it being intuitive, itself requires considerable finessing.

So if your argument is that somehow deflation requires correspondence - and it is not clear that this is your argument - then you haven't gotten very far.

So if your argument is that somehow deflation requires correspondence... — Banno

It seems to me that the T-sentence puts correspondence on display, better than any other way I can see.

Ok, so what is it in the world that makes "the bishop always stays on the same colour square" true? What in the world makes "twice two is four" true? What make "I am Banno" true?

This to show that correspondence, despite it being intuitive, itself requires considerable finessing. — Banno

Fully grasping how correspondence 'fits into' all the different sensible language use is difficult, at best.

The statement about the bishop is true because it corresponds to the rules which determine how a bishop moves. Those rules are part of the world.

The math statement is true for the same reasons.

The claim about your namesake is true because it corresponds to the name you've chosen for yourself, here on this forum.

The deflationary account has issues, but the OP here doesn't talk about them. I've mentioned a few already.

So if your argument is that somehow deflation requires correspondence... — Banno

Language requires correspondence. Deflation requires language. Deflation requires correspondence.

The deflationary theory holds that truth is not a predicate. — Banno

And yet "is true" is. So, "is true" is not equivalent to truth.

However, the cat might not be on the mat, and thus the assertion could be false. What makes the statement true or false? Whether the cat being referred to is actually on a mat. And that's a situation in the world, which we might call a state of affairs or fact of the matter. It is the world which makes statements about the world true or false. But this is the correspondence theory of truth. — Marchesk

You're mixing the two. Deflationism (which has many articulations of course) argues that truth won't play an explanatory role in, say, theories of meaning. Correspondence theorists will say truth has an important role in that discussion. Similarly, for deflationists the entire theory of truth is basically the T-scheme. But for the correspondence theorist, truth can be analyzed in other terms, namely the correspondence relation between sentences (or propositions) and reality. Deflationists often criticize this correspondence relation.

In many ways the difference is just a simplified ontology given the belief we don't need all these extra additions to our metaphysics (e.g. propositions, correspondence, facts and so on).

In many ways the difference is just a simplified ontology given the belief we don't need all these extra additions to our metaphysics (e.g. propositions, correspondence, facts and so on). — MindForged

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

So, how in the world does a deflationist defend the second part if there are no propositions, correspondence, facts or state of affairs? Is it true by definition?

So if your argument is that somehow deflation requires correspondence - and it is not clear that this is your argument - then you haven't gotten very far. — Banno

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

Very well and good. Syntactically, everyone can agree. However,

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

Now you have a disquotation. The left hand side is linguistic, while the right hand side is something else. What is it about the RHS that makes the LHS true? Well, it isn't true simply bu definition, since it's not linguistic. Rather, in this case, it's something about the world.

So then the question becomes how does the world make statements true or false? It's at this point that questions about the nature of truth come into play.

"2+2=5" is false if and only if 2+2 != 5.

Here we the rules of math. In this case, it might seem that 2+2=4 is true by defintion, however, someone can note that when two dinosaurs joined two other dinosaurs in the Jurassic swamp, there were four dinosaurs, not five, long before humans were around to count. And you will have the Platonists talking about how numbers must be something independent of human thought and culture. So again, you have a question about what makes "2+2=4" true.