• Michael
    15.6k
    The T schema does cover both of these cases.Luke

    I meant that when we make sense of the T-schema we cannot simply say that the consequent is a fact because sometimes it isn't.

    For almost every case I can imagine, p is always a fact of our world, our conventions and/or our myths and stories. These might all amount to the same thing.Luke

    Is there some singular term we can use to describe the sort of thing p is? Maybe "narrative"? Sometimes that narrative is a fact and sometimes it is a fiction. Which is really just another way of saying that sometimes the narrative is true and sometimes it is false, making the T-schema just the deflationary theory that the sentences "'p' is true" and "p" mean the same thing.
  • RussellA
    1.8k
    Sometimes something is true because you say it. You cannot apply the above reasoning to everything.Michael

    Agree. Most of the time I accept the names given to things by society, such as ships, tables, governments, etc. However there are occasions when there are no existing words that fit the bill. For example, to make a philosophic point, two years ago I made the performative utterance: "a peffel is part my pen and part The Eiffel Tower". For me, it is now true that the "peffel" is part my pen and part the Eiffel Tower.
  • Moliere
    4.7k
    No theory of truth is going to cover every use of the concept truth. It seems that most uses of the concept, though, do point to a relationship between propositional beliefs, and states-of-affairs. In this sense there is a kind of correspondence or association between the propositional belief, and those states-of-affairs that make the proposition true, as opposed to false. As with the word game, we have a set of family resemblances that guide us when using the concept. There are no hard and fast definitions that work in every social context.Sam26

    Cool.

    So truth is a family-resemblance concept. There are no hard and fast definitions that work for all contexts. So, consequently, there is no universal theory of truth.

    What does that tell us about truth, then? And how are we even able to compare these theories? Is it that there is no truth at all, or an undefined truth? Or is there simply a toy logic we invent in the moment which allows us to temporarily compare these theories among one another, but which ultimately results in no insight -- a formalism of truth?
  • Moliere
    4.7k
    Ok but aren't you rainin' on my parade and on others' parades too? Is there no other way than to just poop at someone's party?

    Beauty, to me, is the very cosmos itself!
    Agent Smith

    Heh, hopefully I'm just making a point about the domain of "P" -- though this is philosophy, and I wouldn't be surprised if I'm on team anti-parade :D
  • Luke
    2.6k
    Is there some singular term we can use to describe the sort of thing p is? Maybe "narrative"?Michael

    Sure, I'm happy to call it "narrative". Or maybe our current conceptual frame.

    Sometimes that narrative is a fact and sometimes it is a fiction. Which is really just another way of saying that sometimes the narrative is true and sometimes it is false...Michael

    I don't agree that the distinction between fact and fiction corresponds to the distinction between true and false. It is true that Mickey Mouse wears red shorts and that vampires have no reflection.

    ...making the T-schema just the redundancy theory that the sentences "'p' is true" and "p" mean the same thing.Michael

    It is redundant if "p" means nothing more than "'p' is true". But this tells us nothing about why "p" might be false.
  • Michael
    15.6k
    I wonder also if the order in which the T-schema is presented affects our interpretation of it:

    a) "snow is white" is true iff snow is white
    b) snow is white iff "snow is white" is true

    As a biconditional both are correct, but I have this intuitive sense that they can be interpreted differently. Perhaps this is related to the paradoxes of material implication.
  • Michael
    15.6k
    I don't agree that the distinction between fact and fiction corresponds to the distinction between true and false. It is true that Mickey Mouse wears red shorts and that vampires have no reflection.Luke

    That's true.

    "vampires have no reflection" is true iff vampires have no reflection
    "snow is white" is true iff snow is white

    The T-schema doesn't really say anything about facts at all. It may, incidentally, be a fact that snow is white (or in some parallel world that vampires have no reflection), but the T-schema is silent on that.

    As I mentioned before, we need a more substantive account of meaning (and perhaps truth) to actually get anywhere important.
  • Luke
    2.6k
    As I mentioned before, we need a more substantive account of meaning (and perhaps truth) to actually get anywhere important.Michael

    That's why I said we should consider why we say that a statement is false. I suggested it could be due to being in conflict with our current conceptual frame:

    For almost every case I can imagine, p is always a fact of our world, our conventions and/or our myths and stories. These might all amount to the same thing.

    Per Wittgenstein:

    241. “So you are saying that human agreement decides what is true and what is false?” — What is true or false is what human beings say; and it is in their language that human beings agree. This is agreement not in opinions, but rather in form of life.
    — Philosophical Investigations
    Luke
  • Agent Smith
    9.5k
    Heh, hopefully I'm just making a point about the domain of "P" -- though this is philosophy, and I wouldn't be surprised if I'm on team anti-paradeMoliere

    The correspondence theory of truth - necessary but not sufficient, ok, but in what sense? Logically, aesthetically, spiritually, for no apparent reason, on a whim, a fancy, what?
  • Joshs
    5.7k


    What does that tell us about truth, then? And how are we even able to compare these theories? Is it that there is no truth at all, or an undefined truth? Or is there simply a toy logic we invent in the moment which allows us to temporarily compare these theories among one another, but which ultimately results in no insight -- a formalism of truth?Moliere

    :up:
  • Moliere
    4.7k
    The correspondence theory of truth - necessary but not sufficient, ok, but in what sense? Logically, aesthetically, spiritually, for no apparent reason, on a whim, a fancy, what?Agent Smith

    Ah, OK -- what's wrong with correspondence. Why bother switching out what works?

    I think that in specifying what correspondence consists in we end up hypostatizing truth -- we treat what is basically conceptual as if it has properties of its own. But I can understand that that's not a universal concern, more of a me-thing. A general suspicion of metaphysical talk is something which is usually in the background of my thinking. Here we end up using "fact" like there are these facts independent of our use of language which secure our language-use. And so correspondence consists in a sort of relationship between Propositions and Facts, both separate one from another.

    But in setting out what a fact is, at least in speech, the facts begin looking pretty similar to propositions. Like there isn't really a difference being drawn as much as we're inventing a story to make sense of this "truth" character.

    We could say, noting their similarity in philosophy, that Facts have a way of invalidating our use of Propositions. So perhaps we cannot say what facts are, but they show themselves at all times.

    But then here we are, a fact among facts interacting with facts -- and nothing really ties "facts" together at this level, no predicate will assemble them all. Especially as you begin to include the not-plums within the ice box. Why not the not-plums differentiated? There were two not-plums in the icebox, one not-green the other purple.

    How many entities can we create with such a logic? An infinite explosion. And what rules would be introduced to stop that?

    This all being an attempt to show there are problems with correspondence as we try to specify exactly what it means insofar that you think an ontology of not-things and not-predicates isn't desirable.
    ...


    There is also the slingshot argument in the back of my mind, given the formalisms. To my mind the only way to stop the slingshot argument is to deny substitutability. But in so denying it seems to me that it's conceded that truth is not universal -- and so we get back to questioning the very rule or intended target of a universal rule of truth.
  • Srap Tasmaner
    5k
    This proposed reduction ignores the fact that 'telling the truth" refers to making a statement about what one honestly believes, and there is no necessary connection between what one honestly believes, and any real "states of affairs".Metaphysician Undercover

    We like to imagine animal signals as, in essence, caused by the occurrence of particular features within the animal's environment. The vervet monkey "emits" a particular sound associated with a particular predator when that predator is present (and, I believe, only when there are other vervet monkeys around to hear it). There is no question of honesty here.

    When we demand (or command, or request, etc.) that someone tell the truth, we are demanding that they behave in a certain way. It would be a senseless demand of an animal that has no choice in the matter. But at the same time, we are demanding that the speaker relinquish their freedom to say whatever they like and instead be bound by the truth.

    If we look at displacement, it may become clearer. If the vervet monkey's calls are caused by their environment, you cannot ask one about a call they made yesterday. In the absence of the stimulus, they simply do not make that call, and the stimulus is in the past. Similarly, you cannot ask such an animal what call they would make if a particular predator were present. If it's not actually present, no call.

    Linguistic animals like us can use displacement though, so we can ask someone to say what they said when they encountered something yesterday. Then we can reason from the words produced to the stimulus present, but only if we trust the link between what you said yesterday and the environment you were in yesterday. That is, only if we believe that, yesterday, on encountering what you did, you had no choice about whether to say what you did.

    In a sense, this is all counterfactual business: you can ask someone to speak as if this situation now were the one they were in yesterday. And, further, if the link between your experience and what you say is not so snug as it is for non-linguistic creatures, we can ask you to behave as if it were. That is, we can ask you to say what you would, if you were in some particular situation, and if you had no choice about what to say.

    On such an account, bizarre and cartoonish though it may be, honesty is a matter of the connection between a, possibly hypothetical or counterfactual, situation and what you would say in that situation. You can interpose beliefs here if you like, but the content of such beliefs goes back to situations. (For it to matter to your speech that you think, correctly or not, this is a snake-situation, you have to know how to speak in snake-situations.)
  • Sam26
    2.7k
    What does that tell us about truth, then? And how are we even able to compare these theories? Is it that there is no truth at all, or an undefined truth? Or is there simply a toy logic we invent in the moment which allows us to temporarily compare these theories among one another, but which ultimately results in no insight -- a formalism of truth?Moliere

    When we talk about truth, we're referring to what people believe. Some theories provide a better answer to the question of truth than other theories. I happen to think the correspondence theory works well.

    Usually when people agree that a particular statement is true, they agree on some fact of the matter. In some cases we're just speculating about the truth, or we are just giving an opinion about what we think is true. In still more cases we may express a theory that X is true, as Einstein did with the general theory of relativity. It wasn't until Eddington verified Einstein's theory that we knew the truth of the matter. Here of course truth is connected with knowledge, not just an opinion or speculation.

    If you want to learn what truth is, then study how the concept is used in a wide variety of situations, i.e., in our forms of life. Think about people disagreeing about political or economic views, they're disagreeing about the facts associated with these views. Most don't know enough to recognize what facts make their belief true or false, so their disagreeing over opinions, and some are willing to kill over their opinions, but I digress.

    What's true can also refer to possible worlds, and to works of fiction. So, there can be facts associated with things that aren't even real. Anything we do is associated with some fact, and as such it can be associated with what we believe.

    There is definitely the concept of truth, so it's not as though the concept doesn't exist, or that it doesn't have a place within our various linguistic contexts.

    Insight is gained by looking carefully at the various uses of these concepts. The problem is that many people want exactness where there is none, at least not in some absolute across the board sense. There are some absolutes when it comes to truth, but those absolutes are relative to a particular context.
  • Agent Smith
    9.5k
    The theory says that a proposition is true provided there exists a fact corresponding to it. — Pie

    This, is it a definition?, breaks down when we take into account the following facts:

    1. How do we determine correspondence with reality? Via observation or more colloquially looking, sensu amplissimo. What about maya?

    2. What about, as I already mentioned, some mathematical truths that have no matching counterpart in reality that has left us guessing is math invented or discovered?

    3. Intriguingly we have the ability to assume a proposition as true, there being no requirement for an assumption to describe reality. Fideism?

    4. Left for the reader as an exercise.
  • Banno
    25k
    The truth is what I say it isRussellA
    You present an argument that language is arbitrary, which in a sense it is, then jump to the non sequitur that truth is relative.

    Is what I say true, trueRussellA
    You present an account of institutional facts, in which the direction of fit is word-to-world. and then jump to the non sequitur that all utterances are of this sort. They are not.

    I comment any of Searle's more recent writings on these topics to you. He explains in detail how these ideas relate. Or you could have another look at my thread on institutional facts.
  • Banno
    25k
    No theory of truth is going to cover every use of the concept truth. It seems that most uses of the concept, though, do point to a relationship between propositional beliefs, and states-of-affairs. In this sense there is a kind of correspondence or association between the propositional belief, and those states-of-affairs that make the proposition true, as opposed to false. As with the word game, we have a set of family resemblances that guide us when using the concept. There are no hard and fast definitions that work in every social context.Sam26

    T-sentences do fit every* case of "'p' is true", but at the cost of triviality.

    But further, as with any term in a language, we don't need a definition in order to be able to use "true". We demonstrate what it means by our use of the term. (PI §201, again)

    The exercise here is to find an appropriate grammar that explicates what is going on. But that is hidden in the discussion, especially by the notion of "correspondence".

    &

    *allowing deranged epitaphs. The Liar paradox being an example.
  • Janus
    16.3k
    I don't think so. Most uses of "truth" point to honesty, as in "are you telling the truth?". It's just a certain type of philosopher, practising a defective form of epistemology, who wants to reduce "telling the truth" to a "relationship between propositional beliefs, and states-of-affairs".Metaphysician Undercover

    What does telling the truth consist in if not giving an honest and accurate account. What does giving an honest and accurate account consist in if not a correspondence of the the account with whatever it is (purporting to be) an account of?
  • Banno
    25k
    "The whole is greater than the sum of the parts" is true ≡ The whole is greater than the sum of the parts.
    To what does this correspond?

    "Frodo walked in to Mordor" is true ≡ Frodo walked in to Mordor.
    To what does this correspond?

    "Frodo walked in to Sydney" is true ≡ Frodo walked in to Sydney.
    To what does this correspond?

    "No bachelor is married" is true ≡ No bachelor is married.
    To what does this correspond?

    "All bachelors are married" is true ≡ all bachelors are married.
    To what does this correspond?

    "This sentence is false" is true ≡ this sentence is false
    To what does this correspond?

    Ands so on. By the time you give an account of correspondence, there is nothing left.
  • Moliere
    4.7k
    I agree with you here, I think. Though we'll see.

    Would you agree in saying there is no universal theory of truth?

    I think the examples elucidate the concept of truth. And, in a given discussion, the examples would elucidate the predicate -B which stands for truth, but with the understanding that it gets updated with every iteration, with every example.
  • Moliere
    4.7k
    You succeeded in derailing my thoughts to Davidson, now. :D I have the book on my table to read A Nice Derangement of Epitaphs.

    We'll see which one gets priority in my too-hard-for-me-now-matrix -- Levinas or Davidson.
  • Banno
    25k
    I'd prefer to say that there is no universal way of determining which statements are true and which are not.

    But that T-sentences are a way of defining truth.

    So we understand what truth is, but not which things are true.

    This comes back to the pivotal distinction between truth on the one hand and belief, justification, warrant and so on on the other.

    So correspondence and coherence and the other substantive theories are theories of belief, justification, warrant and so on, but not of truth. And each tries to limit the determination of which sentences are true, and works, to a point, then fails.
  • Michael
    15.6k
    How does the T-schema deal with self-reference?

    "this sentence has thirty one letters" is true iff this sentence has thirty one letters

    The above sentence has seventy one letters, but the quoted sentence has thirty one. Do we have to make the "this sentence" in the consequent refer only to the consequent and not the biconditional as a whole?
  • Moliere
    4.7k
    But with the caveat of the liars paradox, right? I said it just because it seemed like the most obvious thing that would break the logic.
  • Michael
    15.6k
    But with the caveat of the liars paradox, right? I said it just because it seemed like the most obvious thing that would break the logic.Moliere

    "this sentence is false" is true iff this sentence is false

    If we accept that the T-schema is true then, using the above, "this sentence is false" is false (assuming the consequent is referring to the biconditional as a whole).
  • creativesoul
    11.9k
    The exercise here is to find an appropriate grammar that explicates what is going on.Banno

    That would need to be done with normal everyday language use.

    T sentences are shorthand. I've an issue with the very notion of propositions, so clearly with the accounting practices involving p are included in that, but I'm very fond of the simplicity of Tarksi's formulation, despite not placing as much or the same sort of value upon logic as folks like yourself.
  • Banno
    25k
    "this sentence has thirty one letters" is true iff this sentence has thirty one lettersMichael

    "this sentence has thirty one letters" is true iff that sentence has thirty one letters

    You mucked up which sentence you were talking about.
  • Moliere
    4.7k
    Right.

    And that's somewhat a whole other subset of thoughts on truth -- how to resolve the liars paradox.

    I'd say that's an answer, but I didn't want to go with it because it leads into a whole other topic unto itself. As in, various theories of truth resolve the liars paradox in their own ways. It's not something unique to the formula.
  • Michael
    15.6k
    "this sentence has thirty one letters" is true iff that sentence has thirty one lettersBanno

    That's not disquotation then. It isn't in the form "p" iff p. Yours is "p" if q.
  • creativesoul
    11.9k
    The liar's paradox is not capable of being true or false. Neither are predictions at the time they are made.
  • Banno
    25k
    How does the T-schema deal with self-reference?Michael

    In Tarski's case, by separating the metalanguage from the object language, so that such self-referential sentences cannot be constructed.
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