• Banno
    23.4k
    What makes it valid?

    I say it's that regardless of the interpretation you apply, it turns out true - ones all the way down the truth table.

    What's your definition, such that truth is not involved?
  • creativesoul
    11.6k
    The only way it can be true is to import content beyond what's there, to have a prior understanding that all ms are ps and that all ss are ms. Lacking that, I don't see how any m is a p, or any s an m. It's a form without content. Implied content, sure, if you want, but that;s not the point, is it.tim wood

    So, it's not true by virtue of being the result of valid inference?
  • tim wood
    8.8k
    Validity. I think in terms of the manipulation of symbols according to rules. Would it help to say that validity (under some rule) is truth without content? Will that suffice?
  • Banno
    23.4k
    Given that the discussion is about the circularity of defining truth in terms of validity... not much.
  • Banno
    23.4k
    truth without contenttim wood

    truth is a semantic notion - not just syntax; so it comes into the story along with the content.
  • tim wood
    8.8k
    So, it's not true by virtue of being the result of valid inference?creativesoul

    Ordinarily this question would be out-of-court, but here I have to ask it: what do you mean by "by virtue of"?

    A proposition's being the conclusion of a valid argument allows you to take that proposition as true. If all the concepts are a priori, then it is true. If, on the other hand, the concepts are a posteriori, empirical, contingent, then you may take the proposition as true per argument, but subject to verification. Here we encounter the distinction between logic and rhetoric; the quality of their respective truths is different. Supposing validity and truth to be different things helps keep them straight.

    Supposing them to be the same thing means that all arguments cast in terms of either truth or validity can be recast in terms of the other. Can we really resolve the question of whether to attack at dawn on the same terms of resolving whether 2+2=4?
  • guptanishank
    117
    I am not trying to say why a statement is true.
    Indeed that is a much harder question to answer.
    Logic itself exists because intuitively we as human beings can differentiate between true and false.

    I am just trying to define a true and false.

    That particular circularity between logical validity and truth, I must argue is the minimum that has to be.
  • Banno
    23.4k
    I am just trying to define a true and false.guptanishank

    And there's your problem.
  • tim wood
    8.8k
    truth is a semantic notion - not just syntax; so it comes into the story along with the content.Banno

    Have you resolved your own question? If you have no content, what have you? Answer: form.

    I know you, Banno. You're 173 years old, know everything, and can be found drinking beer under the cool shade of your Baobob tree in your perpetual Australian Summer having fun at our expense while we shovel snow and chip ice at a quarter to six of a cold, dark, Winter morning. But here's the question: can you tell the difference between the beer in the can and the can itself? Such is the difference between truth and validity.
  • guptanishank
    117
    And what may that be exactly?
  • Banno
    23.4k
    Seeking definitions. Bad idea. Gets you in to no end of trouble.
  • guptanishank
    117
    Haha. That is true, but one must seek something in life, and in this one, I sought truth :P
  • tim wood
    8.8k
    I am just trying to define a true and false.guptanishank

    This isn't quite English, or English enough for me to understand it. Are you trying to define the word true and the word false?
  • Banno
    23.4k
    Beer, no so much. Shiraz, thanks.
  • Banno
    23.4k
    Competent speakers of English all, we know what truth is. The hard part is knowing what is true.
  • Banno
    23.4k
    If you have no content, what have you? Answer: form.tim wood

    What could that mean?
  • tim wood
    8.8k
    Seeking definitions. Bad idea. Gets you in to no end of trouble.Banno

    Far more efficient to impose them; that gets you into combat right away.

    Beer, no so much. Shiraz, thanksBanno

    I'm a fan of Lindemnann's cabernet. But in Massachusetts I don't know if what i drink that's represented as an Australian wine is in fact anything to what you-all drink. Maybe you get the good stuff.
  • Banno
    23.4k
    Lindemnann's is a bit pallid; much rather a Coonawarra red.

    The ultimate circularity of definitions should not be much of a surprise. I was thinking more in terms of ostension than imposition.
  • guptanishank
    117
    I think I did get a good enough definition.
    That particular circularity is impossible to avoid, even in Tarski's definition.
  • Banno
    23.4k
    But avoiding it was exactly the point of Tarski's definition.
  • guptanishank
    117
    Tarski also cannot avoid the circularity wrt logical validity eventually.

    Any sentence he forms has to be logically valid, and what does logical validity eventually depend on? Truth.

    There is more than one dimension to this circularity. One cannot avoid all of them.
  • Banno
    23.4k
    You will have to be more specific. What is the circularity you see in Tarski?
  • guptanishank
    117
    Tarski's definition depends on logical validity as well.
    For all x, True(x) if and only if φ(x)
    φ(s) if and only if ψ
    https://plato.stanford.edu/entries/tarski-truth/

    He does assume logical validity after all.
    Although, I must admit that I have not read him completely. Correct me please if you think I am wrong.
  • creativesoul
    11.6k
    So, it's not true by virtue of being the result of valid inference?
    — creativesoul

    Ordinarily this question would be out-of-court, but here I have to ask it: what do you mean by "by virtue of"?
    tim wood

    I find it odd to question the meaning of "by virtue of" and proceed to offer an answer like you did...

    As a result of. Because of.

    The important bit I was getting at was that being the result of valid inference does not make the conclusion true. Earlier you used the notion of what makes a true proposition true. I asked a question about that, but it has not been answered.

    A proposition's being the conclusion of a valid argument allows you to take that proposition as true. If all the concepts are a priori, then it is true. If, on the other hand, the concepts are a posteriori, empirical, contingent, then you may take the proposition as true per argument, but subject to verification. Here we encounter the distinction between logic and rhetoric; the quality of their respective truths is different. Supposing validity and truth to be different things helps keep them straight.tim wood

    I have no idea what you're trying to say with regard to all the concepts being a priori or a posteriori. Nor do I see how such talk helps to understand what truth is ans the role that it plays in everything ever thought, believed, spoken, and/or written. The talk of quality of truth is odd as well.

    Supposing them to be the same thing means that all arguments cast in terms of either truth or validity can be recast in terms of the other. Can we really resolve the question of whether to attack at dawn on the same terms of resolving whether 2+2=4?tim wood

    Whether to attack at dawn is a matter of ought. 2+2=4 simply because we will not let it be any other way.

    Regardless, it seems that we agree that validity and truth are not equivalent, and that being the result of a valid inference does not make the conclusion true(except in the cases you've mentioned where all the concepts are a priori).

    Could you elaborate upon that? I mean what is the criterion which, when met by a candidate, make the candidate a priori?
  • tim wood
    8.8k
    Earlier you used the notion of what makes a true proposition true. I asked a question about that, but it has not been answered.creativesoul

    My sentence was, ""...that which makes individual true propositions true." You're correct, the extra "true" is redundant. In my style manual it says redundancy is not always bad, but it was this time.

    I have no idea what you're trying to say with regard to all the concepts being a priori or a posteriori. Nor do I see how such talk helps to understand what truth is ans the role that it plays in everything ever thought, believed, spoken, and/or written. The talk of quality of truth is odd as well.creativesoul

    Well, let's back up. A proposition can be true or false (either-or), or neither (neither-nor). Folks sometimes forget the neither-nor. We should attack at dawn is a neither-nor. Peanut butter is good for you is neither-nor (bad for folks allergic to peanuts). These propositions are a posteriori, true, that is, depending on circumstances. Neither-nor propositions occur in arguments, sometimes as conclusions. If the argument is valid, then the conclusion follows and is true under the argument.

    For example, it's possible to argue that we should attack at dawn. The argument being valid, then, so far as the argument is concerned, we should attack at dawn. Assuming that what we should do is somehow connected with something to be accomplished, then we will only know whether we should have attacked at dawn after the dawn. If we attack and lose, then the proposition that was true last night was not borne out by events, and in the light of day the truth is that we should not have attacked at dawn. These arguments are made up of contingent premises and lead to contingent conclusions that could be one way or another. Arguments of this form are the province of Rhetoric, which opens out into a whole other topic

    Gold is a yellow metal is true a priori: it's always true. Arguments using propositions that are true a priori, that are valid, yield true conclusions. All men are mortal. Socrates is a man. Socrates is mortal. Now the question: how does the form of the argument make the conclusion true? Answer, it doesn't. The idea is that if the premises are true, and if the argument is valid (form), then you may conclude the conclusion is true. It seems to work. Try writing out any syllogism in valid form where the premises are true and the conclusion false. (Actually, you can prove it by testing all the possible forms of syllogisms, I think there are 256. Apparently Aristotle did that.)

    Ok. Now what is truth. I have argued elsewhere that there is no such thing as truth. It's just a word to collect the idea of true. Propositions are true (or not), this one for this reason, that one for that. The reasons don't have to be the same. True-ness, then, is a quality of propositions. As to there being qualities of being true, there is at least contingent truth along with a priori truth.

    Could you elaborate upon that? I mean what is the criterion which, when met by a candidate, make the candidate a priori?creativesoul

    A priori means universally and necessarily so (in contrast to a posteriori, maybe true, determined by observation/experience).

    If we keep going, I promise to write shorter replies.
  • tim wood
    8.8k
    I was thinking more in terms of ostension than imposition.Banno
    By setting before us the complete sense of the matter in such terms as shall compel our assent?
  • guptanishank
    117
    I'd rather just know if I was right or wrong. But, I guess the answers are more clear in a field like physics, than philosophy.
  • creativesoul
    11.6k
    Earlier you used the notion of what makes a true proposition true. I asked a question about that, but it has not been answered.
    — creativesoul

    My sentence was, ""...that which makes individual true propositions true." You're correct, the extra "true" is redundant. In my style manual it says redundancy is not always bad, but it was this time.
    tim wood

    The question was...

    If that which makes a proposition true differs from true proposition to true proposition, then in what way does it differ? I take it that the answer was the a priori/a posteriori part?


    A proposition can be true or false (either-or), or neither (neither-nor). Folks sometimes forget the neither-nor. We should attack at dawn is a neither-nor. Peanut butter is good for you is neither-nor (bad for folks allergic to peanuts). These propositions are a posteriori, true, that is, depending on circumstances. Neither-nor propositions occur in arguments, sometimes as conclusions. If the argument is valid, then the conclusion follows and is true under the argument.

    For example, it's possible to argue that we should attack at dawn. The argument being valid, then, so far as the argument is concerned, we should attack at dawn. Assuming that what we should do is somehow connected with something to be accomplished, then we will only know whether we should have attacked at dawn after the dawn. If we attack and lose, then the proposition that was true last night was not borne out by events, and in the light of day the truth is that we should not have attacked at dawn.
    tim wood

    I find that the notion of a posteriori as used above conflates different kinds of talk. What should be done is a moral matter. You've contradicted yourself above regarding it. You first said it's a neither/nor matter, but then clearly said the truth of the claim was yet to be determined, but could be. Getting into whether or not an utterance of "should" is true, false, or neither isn't necessary here. It requires a baseline which has yet to have been established. That said, that particular example happens to also be one of prediction akin to saying the sun will rise tomorrow. On my view, it's neither true or false at the time it's uttered. Truth conditions matter.

    "Peanut butter is good for you" is most certainly either true or false, depending upon the person. If it is true, then it is always true. If it is false then it is always false. The claim has different truth conditions depending upon the person being spoken to. If it is stated as a universal, as in it is good for everyone, then it is most certainly false.


    Gold is a yellow metal is true a priori: it's always true. Arguments using propositions that are true a priori, that are valid, yield true conclusions. All men are mortal. Socrates is a man. Socrates is mortal. Now the question: how does the form of the argument make the conclusion true? Answer, it doesn't. The idea is that if the premises are true, and if the argument is valid (form), then you may conclude the conclusion is true. It seems to work. Try writing out any syllogism in valid form where the premises are true and the conclusion false. (Actually, you can prove it by testing all the possible forms of syllogisms, I think there are 256. Apparently Aristotle did that.)

    Ok. Now what is truth. I have argued elsewhere that there is no such thing as truth. It's just a word to collect the idea of true. Propositions are true (or not), this one for this reason, that one for that. The reasons don't have to be the same. True-ness, then, is a quality of propositions. As to there being qualities of being true, there is at least contingent truth along with a priori truth.

    A priori means universally and necessarily so (in contrast to a posteriori, maybe true, determined by observation/experience).
    tim wood

    Learning the definitions of terms is determined by experience. A priori is 'true' by definition. I'm still wondering how this relates to a syllogism, because you earlier said that if all the concepts are a priori then a valid form will yield a true conclusion. Premisses are not concepts.

    A different tack will help, I think. We are discussing logical truth, which involves an argument. We are talking about the different kinds of premisses that a syllogism can have, notably what makes them true. However...

    A true statement does not require logic. Thus, either truth does not require logic, or true statements do not require truth.
  • tim wood
    8.8k
    If that which makes a proposition true differs from true proposition to true proposition, then in what way does it differ?creativesoul
    Best you work this through yourself. Pose any true propositions you like, then ask yourself what makes them true.
    What should be done is a moral matter.creativesoul
    Always?
    A different tack will help, I think. We are discussing logical truth, which involves an argument. We are talking about the different kinds of premisses that a syllogism can have, notably what makes them true. However...

    A true statement does not require logic. Thus, either truth does not require logic, or true statements do not require truth.
    creativesoul
    Syllogisms are never true, they're just valid in form , or not. "Premise" names a proposition in use in a syllogism: the first (major), or the second (minor). All propositions in syllogisms are of the form (All, some, no) S are (are not) P. The conclusion is also a proposition. The premises are presumed true (axioms or theorems). Their truth and use in a valid argument warrants the truth of the conclusion.

    If you have thought about what makes true propositions true, then you recognize that logic - organized thinking - may well underpin some true propositions. So the determination that a proposition is true may well require some logic. As to anything about truth, you might want to try to define it first - good luck with that. Post here if you come up with one!

    And we've referenced rhetoric along with logic. They both treat of reasoning with propositions. But the propositions differ and thereby the treatment differs - with some overlap to be sure. It's all too easy to get confused if the two are spoken of as if interchangeable.
  • creativesoul
    11.6k
    f that which makes a proposition true differs from true proposition to true proposition, then in what way does it differ?
    — creativesoul
    Best you work this through yourself. Pose any true propositions you like, then ask yourself what makes them true.
    tim wood

    Here's the thing. You're working from a framework of propositions being the things that can be true/false. I do not. I have worked through the question myself. The answer you've given is unacceptable. I'm asking how your framework accounts for the assertion you made. That's a perfectly acceptable thing to do given the situation. It's your claim, your justificatory burden.


    A different tack will help, I think. We are discussing logical truth, which involves an argument. We are talking about the different kinds of premisses that a syllogism can have, notably what makes them true...
    — creativesoul

    Syllogisms are never true, they're just valid in form , or not.
    tim wood

    Poor wording on my part. I meant... notably what makes the different kinds of premisses true. You ought have known that, given the talk of a priori and a posteriori.


    The premises are presumed true (axioms or theorems).Their truth and use in a valid argument warrants the truth of the conclusion.tim wood

    Of course we presuppose the truth of the premisses. If they are true, and the argument valid, then the conclusion is true. Warrant is about belief, not truth. True premisses and valid argumentative form warrants belief that the conclusion is true. Belief is not truth.


    If you have thought about what makes true propositions true, then you recognize that logic - organized thinking - may well underpin some true propositions. So the determination that a proposition is true may well require some logic.

    Can you provide an example of such a proposition?


    As to anything about truth, you might want to try to define it first - good luck with that. Post here if you come up with one!

    Sigh. Pots and kettles. Aren't you actively employing the term? You can replace the term "truth" with "correspondence" anywhere in my writing usually, although I do occasionally follow suit. I am quite cognizant of that.
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