• Isaac
    10.3k
    Isn't that exactly how you use it when you speculate (with or without committing) as to the relative merits of competing (and perhaps currently unfalsified) theories?bongo fury

    I don't think anyone would use 'true' in that situation. 'Likely' maybe, or 'possible'. Either way, I'm not ruling out niche cases, only aiming at a summary of normal use.

    I'm always surprised when anyone takes "what they do mean" to be a matter of fact.bongo fury

    Being interested in the question and presuming the answer is a matter of fact are not the same thing. I think we can say it's a matter of fact that 'game' does not mean [small bag for keeping a wallet in]. We can discover this 'fact' empirically. That doesn't mean we now know everything 'game' does mean, but our investigation has certainly given us something useful about the word. We can continue this way with any unfamiliar or troubling word in the hope that situations describing its normal use can help dissolve problems associated with its abnormal use.
  • frank
    15.8k
    so that’s a planet we would see if we went there. Same as a cup we would see if we opened the cupboard.Banno

    It's a planet we can't in principle know about, in the past or during the heat death of the universe where it's expanded to the point that it's impossible to travel there. Or it's cloaked by the Romulans.

    The point is: we can't observe it, so we cant know about it. Dummett isnt saying planets are dependent on observers, he's questioning the meaningfulness of talking about what we cant know.

    This is a cool summation of why we might relate meaning to truth conditions:
  • frank
    15.8k
    What is so hard about that? Why complicate things by bringing in all this talk about 'truth'?A Seagull

    Because it's fun.
  • frank
    15.8k
    But it's the reason some people claim string theory doesn't qualify as science: because it can't presently be verified.
    — frank

    I thinks it's rejected because it is thought that it cannot be verified (or falsified) in principle,as opposed to merely "presently".
    Janus

    O'Dowd of PBS Spacetime says we might develop a way to test it in a thousand years or so. He emphasizes that the universe is not obligated to make all of its aspects observable to us. I'm in no position to judge it for myself.
  • Janus
    16.3k
    The way 'truth' is most commonly used is simply that it consists in what says how things really are.

    In other words its logic is one of correspondence, as formulated by the T-sentence.
  • Janus
    16.3k
    If it could be tested in principle then it could be true or false. Those who say string theory is not even wrong are claiming, whether rightly or not, that it is not testable in principle. A statement or theory which is not testable in principle would be deemed to be inconsistent with the common notion of truth.

    Does this mean the statement must be incoherent? I don't know, but (as far as my limited knowledge of it goes) I don't think string theory is incoherent. If that's right does that mean it is testable in principle? How would we know if something is testable in principle, anyway? Would or should it be deemed to be untestable in principle, just because we cannot presently imagine any possible way it could be tested?
  • IvoryBlackBishop
    299

    ↪frank If it could be tested in principle then it could be true or false. Those who say string theory is not even wrong are claiming, whether rightly or not, that it is not testable in principle. A statement or theory which is not testable in principle would be deemed to be inconsistent with the common notion of truth.

    That's based on a particular system or methodology of testing, invented from pure mathematics, based on axioms and particular standards and methods of testing (e.x. induction), when of course the defintions of testing themselves can be changed or redefined, much as how Bacon's method defined them to begin with.

    So in practice, when hear this argument, it generally strikes me as blind faith (rather than experience) in a particular system, or institution of testing and testability, however the prime truths or axioms upon which said system was mathematically built upon to begin with are held to be absolute, at least as in regards to the scope or proceedures of the method itself, in a way which is completely independent from testing.

    (Since the prime truth or axiom that Bacon's 17th century method based on induction is how things should be tested to begin with, is not in itself testable but merely held either to be knowable a priori, or based on an argument from authority on behalf of Bacon's wisdom, or that of those who practice his method).
  • Isaac
    10.3k
    The way 'truth' is most commonly used is simply that it consists in what says how things really are.Janus

    Well that can't possibly be the case because otherwise we'd never use it. We don't know how things really are, we only know how we believe them to be, so 'true' would correspond with our beliefs, not the world.
  • A Seagull
    615
    What is so hard about that? Why complicate things by bringing in all this talk about 'truth'? — A Seagull
    Because it's fun.
    frank

    Well I congratulate you! It is good to find fun in the little things, but personally I have had more fun having a root canal. :)
  • Janus
    16.3k
    People may justifiably think they know the way things really are. This is not problematic when it comes to everyday observable matters; whether it is raining, whether Paris is the capital of France, whether someone owes you money, whether cars commonly are powered by internal combustion and so on for countless details about the world of everyday common experience.

    The skeptical concern that we may not know how things "REALLY" are is based on the assumption that things really are some way, and this doesn't at all change the fact that truth, whatever it might be, whether known by us or not, is thought to accord with the way things really are.
  • Isaac
    10.3k
    this doesn't at all change the fact that truth, whatever it might be, whether known by us or not, is thought to accord with the way things really are.Janus

    'Truth', in the sense you're referring to it here, is a category in which we place certain propositions and from which we reject others. To say ""Paris is the capital of France" is true", is to say that the proposition "Paris is the capital of France" belongs in that category {propositions which are true}. Philosophically, I'm happywwith the deflationary position, the "is true" bit adds nothing ontologically. But as a linguistic expression, the above categorisation is what it's mostly doing. It's how we can use it even circumventing deflation in "everything he just said was true".

    But in order to use a category, we must know what the criteria for membership are. If the criteria for membership were {things which really are true} then we should not be able to put anything in that category. At best it can be {things we're happy to assume are the case}. It can only ever be about belief/judgement because that's all we have, we cannot check with some higher authority.

    Nor can we appeal, in claiming truth of our proposition "P" to an accord with the fact that P, because to say it is a fact that P is just to assert P.

    I really don't understand whysso much mental effort is put into this convoluted project of trying to rescue the divinity of the term 'true' from the clutches of the evils of justified beliefs. Some leftover of religious certainty our secular culture is still trying to fill, I think.
  • Janus
    16.3k
    But in order to use a category, we must know what the criteria for membership are. If the criteria for membership were {things which really are true} then we should not be able to put anything in that category. At best it can be {things we're happy to assume are the case}. It can only ever be about belief/judgement because that's all we have, we cannot check with some higher authority.Isaac

    I think it's not a matter of knowing which things can be put in the category "true", but of defining what criteria justify anything being in that category. So, the common logic is "accordance with actuality". As I said before; in countless ordinary cases we know what accords with actuality as long as we don't try to introduce some radical (and mostly inappropriate) skepticism as to what "really" constitutes actuality.

    In other cases, for example, propositions about the nature of distant galaxies which we cannot observe at all because they are beyond the "light horizon", we can say that there would be actualities about which true or false statements could be made if only we were there to observe them.

    I really don't understand whysso much mental effort is put into this convoluted project of trying to rescue the divinity of the term 'true' from the clutches of the evils of justified beliefs. Some leftover of religious certainty our secular culture is still trying to fill, I think.Isaac

    I think the reason is that it is important to acknowledge that there are actualities which are independent of human opinion. In some sense truth just is actuality. But we think of actuality as different to truth in the sense that truth consists in what can rightly be said about actuality.

    The inherent logic of this doesn't change even if it is accepted that there must be actualities about which we cannot say anything at all.
  • Janus
    16.3k
    Not clear what you are trying to say here.
  • Isaac
    10.3k
    I think the reason is that it is important to acknowledge that there are actualities which are independent of human opinion. In some sense truth just is actuality. But we think of actuality as different to truth in the sense that truth consists in what can rightly be said about actuality.Janus

    Important or not, it simply cannot be done and, especially in philosophy, I'm just not seeing the merit in being inaccurate for the sake of...what, exactly?

    When we say a proposition is 'true' we are saying that we believe it accords with reality. It is a statement about our judgement, not about the world. "the cat is on the mat" is a statement about the world. ""The cat is on the mat" is true", is a statement about how I feel about the statement "the cat is on the mat". I don't see how anyone can deny this is what's happening - "...is true" means "I believe it".

    The objection that people can be wrong about what is true ""the earth is flat" is true", is no more troubling than that people can say " discos are fun". They're wrong, discos are not fun - except they are fun for them.

    Now you can argue that 'fun' is subjective, but what evidence would you bring to bear to prove that? That people disagree about what's fun? Well they disagree about what's true too. That fun describes a state of mind? Well believing a statement to be true also describes a state of mind.

    As Ramsey said "it is‘immediately obvious that if we have analysed judgment we have solved the problem of truth"

    I get that a distinction is useful between those things only a few crackpots believe and those things which the vast majority of well-educated people believe. I'm perfectly happy that in general colloquial use 'true' is used to make that distinction . Here 'true' is used to mean "this proposition has a good standard of justification". I'm fine with that, but...

    If we reject scepticism about actuality, then that might well serve the interests of philosophers who want to get get on with the business of telling people what's what, but it doesn't very well serve the interests of psychology or neuroscience. You may think that...

    in countless ordinary cases we know what accords with actualityJanus

    ... but you really don't. I could set up a situation in the space of a couple of hours wherein you'd be convinced the cat was on the mat when in fact there was no cat. Suggestion, priming, false memory creation...Give me a few years and I could have you seeing cats everywhere. The point is, this is not because of some psychological trick I could play on top of, or masking, your normal accurate methods of recognising reality, It's because your normal methods of recognising reality do all this fabrication anyway. You really don't see a cat (as in pick up all the light waves reflected from the shape of the object). You make up that a cat is probably there from a few sketchy outlines and a lot of prior expectation and then you don't even bother checking unless something gives you reason to. That is - by the best science we currently have - actually how your perception works.

    Now that being the case, what are the psychologist and the neuroscientist supposed to do with a definition assuming what we perceive accords with what is actually the case? If we reject scepticism, how are we supposed to talk about the state of affairs scientific investigation of the brain is revealing to us?
  • A Seagull
    615
    You make up that a cat is probably there from a few sketchy outlines and a lot of prior expectation and then you don't even bother checking unless something gives you reason to. That is - by the best science we currently have - actually how your perception works.Isaac

    IMO the only way that it can be logically inferred that a 'cat is on a 'mat' is from a boot strap process of pattern identification from sense data. I discuss this in some detail in my book 'The Pattern Paradigm'.
  • Qwex
    366
    Truth is a matter of detection.

    "Is X true?" is a question that must resound in all truth qualititive statements.

    It's true that grass is commonly green, in response to 'is X true?'.

    If I had said this without the resounding question, it may not have any context.

    The grass is green, thus, in response to "is X true?", I would say it's true the grass is green.

    If I hold a truth - I may not just as well hold reality - truth can make reality more personal.

    It has value but it's not to be confused with reality. Why would we hold truth? It helps us detect falsehoods.
  • Janus
    16.3k
    When we say a proposition is 'true' we are saying that we believe it accords with reality. It is a statement about our judgement, not about the world.Isaac

    No, when we say a proposition is true we are saying that it accords with reality, not merely that we believe it accords with reality. If I say that it is true that Donald Trump is POTUS, I am not saying (only) that I believe that Donald Trump is POTUS, but that Donald Trump is POTUS. You are conflating belief with actuality.

    It doesn't matter that I might not know what the actuality is. When I make a statement about what is true, my intention is to say what is true, not merely to say what I believe is true. On a "meta-level" what I am saying may be merely an expression of my belief (it also may happen to be an expression of the truth, even if I can never be certain that it is). But that "meta-caveat" is not the same thing as the logic that is inherent in the intention underlying truth-statements. You are conflating the two.
  • A Seagull
    615
    It doesn't matter that I might not know what the actuality is. When I make a statement about what is true, my intention is to say what is true, not merely to say what I believe is true.Janus

    But then you are entering a world of fiction, fantasy.
  • Janus
    16.3k
    Why do you say that?
  • A Seagull
    615
    Because if you choose to believe something for which there is no rationality, then you leave the rational world and enter a fantasy world.

    And there is no rationality that can show how any statement can have a direct correspondence to the 'world of actuality'.
  • Janus
    16.3k
    I haven't said anything about "showing how any statement can have a dierct correspondence to the world of actuality"; whatever "showing" in such a context could even mean or consist in!

    I've said that the way we commonly talk and think about truth presupposes an actuality that our statements are either in accordance with or not. That accordance or lack of accordance just is what we mean by truth and falsity respectively. The logic of accordance is the logic of the relationship between truth and actuality, between propositions or statements and things and events, as we commonly understand it.

    The point is that it can't be justified or "shown" from some position outside it, some "god's eye" view, but only from within the logic and facts of everyday practice. In fact it's not a matter of justification at all, as I see it; if you start thinking in those terms, you have already gone astray.
  • Marchesk
    4.6k
    And there is no rationality that can show how any statement can have a direct correspondence to the 'world of actuality'.A Seagull

    It's pretty easy to show how "Donald Trump is POTUS" is true, though. If I said instead, "Alien life exists out there.", then your criticism would apply, as we don't have any way of justifying that statement, so we don't know the truth of the matter.

    Now if I knew you were guessing that about the president of the US, but didn't really know, then it would be a matter of belief.
  • A Seagull
    615

    It is the interpretation of the statement (as opposed to the statement itself) and its correspondence to one's model of the world that enables it to be labelled as true.

    The statement itself consists of a string of alphanumeric characters and has no direct correspondence to the world except through its interpretation.
  • A Seagull
    615

    You are referring to the common or normative usage of the word 'true', in which case I would agree with you. But it is IMO a naive usage. It works fine for most people, but on closer examination for philosophy, it is plain that one only knows a model of the world rather than the 'actuality of reality'.

    It is akin to whether one believes the Sun goes around the Earth or not. For most people the idea that the Sun goes around the Earth works fine (or at least it did in the past) but on closer examination for the purposes of astronomy one learns that that model is ineffective.
  • Janus
    16.3k
    You are referring to the common or normative usage of the word 'true', in which case I would agree with you. But it is IMO a naive usage. It works fine for most people, but on closer examination for philosophy, it is plain that one only knows a model of the world rather than the 'actuality of reality'.A Seagull

    The idea, though, is that there is an actuality which we could, in principle, experience and know more comprehensively, that what we now experience and know is not exhaustive. It's an entirely different idea that there is an actuality or an aspect of actuality (the "ding an sich", for example) that we could never in principle, experience and know.

    We know what we perceive, but we cannot hold what we perceive up for comparison against some purported thing we cannot, in principle, perceive. The very idea of something we cannot in principle perceive is incoherent. How could such an idea itself reflect reality?
  • Gregory
    4.7k


    The idea reflects itself in the imagination the way poetry works

    "As something factical [real, factual], the understanding self-projection of Being is always already together with a discovered world." Heidegger

    Yet how can you be together with what you are? Welcome to modern philosophy my friends, a beautiful garden. When Hegel says the world is thought, he in no ways means it, yet he does. Modern philosophy deals with the accidents of truth, and in the end rejects the substance, creating a self-consistent system that sounds like a Buddhism traditional sung mantra
  • A Seagull
    615

    OK perhaps I misunderstood you.

    Certainly as part of ones model of the world is the idea that there is a real world out there that one can learn about and improve one's model.
  • Janus
    16.3k
    I'm not quite sure what you're saying, but it sounds poetic!
  • Isaac
    10.3k
    when we say a proposition is true we are saying that it accords with reality, not merely that we believe it accords with reality.Janus

    Interesting. So you're saying that 'believing' is one attitude we can have toward a proposition's content, but there's some other attitude we can have toward it which you're saying is the one we use to apply the label 'true'? Do you have a name for this other attitude? When does it kick in?

    Let's take your example of a 'truth',"Donald Trump is POTUS". If, after the election, a friend tells you that "Donald Trump is POTUS", do you merely believe that this accords with reality, or do you have this other attitude yet? If not yet then maybe you read it in the paper. Do you now have this attitude. I'm intrigued as to what point a mere belief transitions into this other attitude, but more importantly, I'm intrigued as to how you distinguish between the two.

    It's possible the answer to all these questions is actually in your last paragraph, but if so, I'm afraid I couldn't make any sense of it, so I'd be grateful for a re-wording.
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