Bob believes P is true while not-P is true. — Pie

What does "not-P is true" mean according to the deflationist?

What does "not-P is true" mean according to the deflationist? — Luke

I can can't speak for others, but I'd say it means the same thing (roughly) as not-P.

It's true that it's not raining.
It's not raining.

I can speak for others, but I'd say it means the same thing (roughly) as not-P. — Pie

According to who is not-P true? If it's not Bob endorsing not-P, then who is?

'P is true',if spoken by Bob, is roughly equivalent to Bob saying 'P' or endorsing 'P' when said by someone else, perhaps with a 'yes indeed.' — Pie

My point is that when you say "...but not-P is true", then you are using "is true" in a non-deflationary way.

I don't see that. for me, the words on the right of "iff" in '"Snow is white" is true iff snow is white' point to the grounding fact of snow being white (or not). — Janus

That "grounding fact" might be that the sentence "snow is white" coheres with some specified set of sentences, à la coherence theory.

a. "snow is white" is true iff snow is white
b. snow is white iff "show is white" coheres with some specified set of sentences
c. Therefore, "snow is white" is true iff "show is white" coheres with some specified set of sentences

The T-schema of (a) works with any number of more substantive views of truth. (b) can be thought of a theory of meaning that adds to the rather empty theory of truth given by (a).

Alternatively:

a. "snow is white" is true iff snow is white
b. snow is white iff the mind-independent material world is a certain way
c. Therefore, "snow is white" is true iff the mind-independent material world is a certain way

That would be closer to the traditional correspondence theory.

"snow is white " is true iff s..........All we need to do now is work out what s might be. — Banno

My attempt:

I believe that I am observing something that is atmospheric water vapour frozen into ice crystals and falling in light white flakes or lying on the ground as a white layer

Rather than keep saying "I believe that I am observing something that is atmospheric water vapour frozen into ice crystals and falling in light white flakes or lying on the ground as a white layer" it is more convenient to say "I believe that I am observing snow"

Where "snow" is defined as "something that is atmospheric water vapour frozen into ice crystals and falling in light white flakes or lying on the ground as a white layer".

In other words, "white" is part of the definition of "snow".

I need no knowledge of the world to know that "snow is white", only knowledge of language.

In Tarski's terms, I can say "snow is white" and a German can say "schnee ist weiss". These are said within the object language

The metalanguage is where words are defined, in that "white" is part of the definition of "snow", "white" means "weiss" and "snow" means "schnee"

Therefore, we can replace "snow is white" is true iff s by "snow is white" is true iff "white" is part of the definition of "snow", "white" means "weiss" and "snow means "schnee"

Therefore s = the linguistic declaration that "white" is part of the definition of "snow", "white" means "weiss" and "snow" means "schnee".

Perhaps unsurprisingly, I have a different view. For me knowledge is about certainty, certainty that is, not in any "absolute" sense, but in the context of everyday experience. If I see plums in the fridge, I am certain they are there. If I close the fridge door, and am still standing in front of the fridge I am virtually as certain that they are there. If I leave the room for a few moments and then return, I might still be almost as certain. If I left the room for an hour, and was confident no one else was around then I might still be almost as certain. And so on. But I would say that I only know, that is I can only be certain ( i.e. without any attendant doubt) that they are there if I am looking at them. Once I step away, knowledge steps aside with me, and belief kicks in, to be assessed as more or less justified. — Janus

The issue you describe here is a problem with the justification. The justification is somewhat faulty and therefore truth in the matter cannot be ascertained. This allows for the encroachment of doubt and skepticism.

The justification is based in our ideas of temporal continuity, inertia, which are well represented by Newton's first law. Principles such as this law tell us that a thing will continue to exist, exactly as it has in the past, unless it is caused to change. This is the temporal continuity of existence which forms the foundation for that justification. And, since your observations apprehend nothing which would cause such a change, you conclude that the plums are still in the fridge.

We can see that the fault in this justification lies within the assumption that a change to the temporal continuity of existence would necessarily be observed by you. Since this is a required premise in that justification, and it is not a sound premise, truth cannot be ascertained through that justification, and doubt is summoned.

We can ask what such a theory might look like. If it is adequate to its task, it will deliver, for every sentence, something that tells us if that sentence is true.

So it will have the form

For any sentence p, p is true if and only if ϕ

Further, to avoid circularity, the notion of truth cannot occur in ϕ.

And finally, this will not work for a language strong enough to talk about its own sentences, because directly it will be able to generate a sentence of the form — Banno

This will never work, because "truth" is a feature of particular circumstances, and the accidentals of particular circumstances cannot be captured in a universal statement such as you propose. Therefore your enterprise is doomed to failure.

You might however, change your definition of "truth", such that truth is not a feature of particular circumstances, and define it so that it is a feature of some sort of universal statement or generalization, thereby creating the illusion that success is possible, but that would really be a failure as well.

I would like to ask what category of question this is.
Is it a metaphysical question?

Is there any practical difference between understsnding the logic of truth, and how to know the truth?

How do we verify our truth theory, if its pure metaphysics?
Since a foundation of metaphysics is required before we can epistemologically test if a statement is true, then how do we test metaphysical foundations?

How do we verify our truth theory, if its pure metaphysics? — Yohan

This reality, then, that gives their truth to the objects of knowledge and the power of knowing to the knower, you must say is the idea of the good, and you must conceive it as being the cause of knowledge and of truth in so far as known. Plato, Republic, 508e, Republic II.

My point is that when you say "...but not-P is true", then you are using "is true" in a non-deflationary way. — Luke

Your critique(Pie's claim) reminds me of Moore's paradox.

Is there any practical difference between understanding the logic of truth, and how to know the truth? — Yohan

A twenty-seven-month-old child can know when "there's nothing in there" is false, when the speaker is talking about a fridge. I gave that real life example earlier. She demonstrated that knowledge. She has no idea whatsoever about theories of truth. The terms "truth" and "falsehood" are not even understood by her. She certainly does not understand the logic of truth.

A twenty-seven-month-old child can know when "there's nothing in there" is false, when the speaker is talking about a fridge. I gave that real life example earlier. She demonstrated that knowledge. She has no idea whatsoever about theories of truth. The terms "truth" and "falsehood" are not even understood by her. She certainly does not understand the logic of truth. — creativesoul

Which is why use tells us much more about these concepts, i.e., tells us much more about meaning and understanding.

Truth is not belief - already covered:
Truth is a unary. T(p) is a general representation of the statements, propositions, sentences, facts, or whatever you will, that we cast as true: "p is true"

Belief is binary. B(x,p) is a general representation of the statements, propositions, sentences, facts, or whatever you will, p, that we cast as being believed by x. "x holds that p is true"
— Banno

Further, one chooses between a realist and an antirealist grammar. The best grammar for cats and mats is realist. — Banno

This is about our accounting practices. It restricts and/or limits all belief to propositional attitudes. While this is little to no problem at all if we're talking about language users who have and or develop propositional attitudes, it is quite problematic if we're talking about creatures that are incapable of having a propositional attitude but are perfectly capable of believing that a mouse is behind the tree, that a lizard is under the stove, that a dog is in the house, that food is in their food bowl, or that another cat is on the bed. So, while it works well for analyzing belief statements, the grammar of belief being put to use here is inherently inadequate for taking proper account of language less creatures' belief. It's found lacking in explanatory power.

Cats do not have an attitude towards propositions. They do not hold propositions as true. The T sentence cannot properly account for creatures incapable of having propositional attitudes, and thus, we cannot rightfully encapsulate a cat's belief within quotes on the left side as we do with language users for that would be a mischaracterization of the cat's belief(an accounting malpractice when used in such a way). However, and this is very interesting to me, when we do talk about what it would take in order for a cat's belief to be true, we find ourselves saying much the same thing as we do when it comes to propositional attitudes, despite the fact that cats are incapable of having and/or developing them.

Cookie's belief that a dog is in the house is true only if, only when, and only because a dog is in the house.

Such are the kinds of belief that some language less creatures are capable of forming, having, and/or holding. Much like us, they are more than capable of forming, having, and/or holding belief about what's going on around them. Unlike us, they are incapable of talking about their own thought and belief as a subject matter in its own right. Unlike us, they are incapable of considering what sorts of things can be true, and what it takes in order for them to be so. Unlike us, they are incapable of doubt and/or skepticism. Much like us, they are capable of forming, having, and/or holding true belief, false belief, as well as belief that is neither at the time(in the case of expectation).

Again, I find it very interesting that our analysis of what sorts of things can be true and what makes them so has no issue at all exhausting some language less creatures' belief, so long as it's not formal logic being used. Common language works just fine.

A twenty-seven-month-old child can know when "there's nothing in there" is false, when the speaker is talking about a fridge. I gave that real life example earlier. She demonstrated that knowledge. She has no idea whatsoever about theories of truth. The terms "truth" and "falsehood" are not even understood by her. She certainly does not understand the logic of truth.
— creativesoul

Which is why use tells us much more about these concepts, i.e., tells us much more about meaning and understanding. — Sam26

Hey Sam!

Indeed. It's puzzling how a child that can barely string two or three words together knew when she heard the claim that it was not true, and then went on to demonstrate that much, and yet highly educated people seem to have talked themselves right out of that.

I think that that qualifies for Witt's notion of bewitchment. The story may be able to tell us something about hinge propositions???

a. "snow is white" is true iff snow is white
b. snow is white iff the mind-independent material world is a certain way
c. Therefore, "snow is white" is true iff the mind-independent material world is a certain way

That would be closer to the traditional correspondence theory. — Michael

It doesn't need to be "the mind-independent material world" and cohering with "some specified set of sentences" is not enough; simply being in accordance with what is experienced will do. People see snow, even if only in pictures, and it is generally white, so all one needs to know in order to understand that ":snow is white" (taken as a broad statement) is true is that snow is white.

Even children would know "snow is purple" is not true, just on account of having seen snow. On the other hand if you spray painted some snow purple, and then said "this snow is purple" of course again, even a child (who understands the words you uttered) will agree that would be true.

We can see that the fault in this justification lies within the assumption that a change to the temporal continuity of existence would necessarily be observed by you. Since this is a required premise in that justification, and it is not a sound premise, truth cannot be ascertained through that justification, and doubt is summoned. — Metaphysician Undercover

You are taking the radical skepticism position I have already said I'm not concerned with. I'm not concerned with it because there are no known instances of "changes to the temporal continuity of existence", which means we have no reason to take their possibility into consideration. If we do find one, then we can start worrying about it.

As I already said I am concerned only with the context of everyday experience. since this is the context in which propositional statements and our judgements about their truth find their relevance.

Perhaps it would be most accurate to say that deflationary theories remain incomplete, but offer a better account that any other theories. — Banno

This is how I feel about them.

The only thing wrong with deflationary theories is they are obviously false. But that's a feature, given how the others are inobviously false, and you really get a close approximation.

Madness amongst the mods.

We are apparently banned from discussing the logic of truth. :roll:

The only thing wrong with deflationary theories is they are obviously false. — Moliere

So can you set out, succinctly, why they are wrong? Not that I disagree...

Indeed. It's puzzling how a child that can barely string two or three words together knew when she heard the claim that it was not true, and then went on to demonstrate that much, and yet highly educated people seem to have talked themselves right out of that. — creativesoul

Isn't part of this because they have taken Plato's cave allegory to heart? The assumption being that those illusory shadows are everywhere and that only adults and smart people can work to discover the truth behind the deception of appearances.

There you go again, claiming belief is not propositional then giving examples of animal beliefs, as if "the mouse went behind the tree" were not a proposition.

I'll leave you to it.

All this shows is your lack of familiarity with work of Tarski.

THis was addressed to my opening post on the now closed thread on the logic of truth..

Is there any practical difference between understsnding the logic of truth, and how to know the truth? — Yohan

Yes. Logic is a seperate topic to metaphysics and epistemology. What is discussed there is in effect the grammar of the topic, the ways on which we can put sentences together coherently.

There are a number of different ways of treating truth, that have ben expounded in logical terms. These relate to, but differ from,how we know something is true, the topic of epistemology, and the the sort of things that are true, the topic of metaphysics.

@Michael hasn't understood this, either.

Indeed. It's puzzling how a child that can barely string two or three words together knew when she heard the claim that it was not true, and then went on to demonstrate that much, and yet highly educated people seem to have talked themselves right out of that.

I think that that qualifies for Witt's notion of bewitchment. The story may be able to tell us something about hinge propositions??? — creativesoul

This apparently ruffled some feathers when I said it, way back when, eight days ago:

The dogma of the linguistic keeps some in their slumber. — Fooloso4

You have a science background, yes?

What you have written is a start, but there is much conceptual refinement that is missing.

You might enjoy Quine's two Dogmas of Empiricism. It is a critique of the analytic-synthetic distinction, and of reductionism.

Your post seems to make use of both.

I'm not concerned with it because there are no known instances of "changes to the temporal continuity of existence", which means we have no reason to take their possibility into consideration. If we do find one, then we can start worrying about it. — Janus

I am talking about everyday occurrences. And yes, there clearly is changes to the temporal continuity of existence of things, that\s what "force" does. By Newton's laws, "force" is required to alter the temporal continuity of existence of a thing. This is known to us as "change".

So your plums in the fridge will continue to exist in the same way that they were put there, until a force is applied. Now the issue is whether the force required to substantially alter the existence of those plums, is necessarily observable to you watching the fridge from the outside. Well, the plums will rot, even in the fridge, and this change is not observable to you from outside the fridge. That's clear evidence that the justification for your assumption that the plums will continue to exist, as you left them, is faulty. There are unperceived forces being applied to those plums all the time, altering the continuity of their existence.

Isn't part of this because they have taken Plato's cave allegory to heart? The assumption being that those illusory shadows are everywhere and that only adults and smart people can work to discover the truth behind the deception of appearances. — Tom Storm

Perhaps.

I think Searle has it right when he talks about the mistakes that have been repeated, in some form or another, for hundreds and hundreds of years. It pleases me that a highly respected authority has so much to say that dovetails nicely to my own position.

Our report of a cat's belief comes in propositional form. Cats cannot have attitudes towards propositions such that they take them to be true. You know that.

Cookie's belief that a dog is in the house is not an attitude that she has towards that proposition such that she holds it as true. Rather, it's more of the direct presentation of the dog being in the house. Searle's account of direct perception and intentionality works well here. I've been watching Searle, being the exciting guy that I am...

Good, keep watching Searle. He'll help you work through this incoherence.

There was a quote...

Here I was hoping to attain mutual concessions in order to further the discussion beyond the sticking points we always seem to arrive at. I am willing to concede that language less belief can be put into propositional form. I was hoping at least that you would concede that a language less animal is incapable of having attitudes towards propositions.

The insult is petty and it's not true. Ah well...