• Isaac
    10.3k


    So a belief that's well justified is 'true'?

    Then what purpose does 'true' serve in 'Justified True Belief', that is not satisfied by 'Justified Belief'?
  • Michael
    15.4k
    So a belief that's well justified is 'true'?Isaac

    No, but if one has a justified true belief then one has ascertained that one's belief is true.
  • Michael
    15.4k
    Are you saying that someone, in the real world, can know (with certainty) what the rules of a game are without ever being told what the rules are?I like sushi

    I don't know about with certainty, but they can know the rules of a game by watching the game and learning how it's played. If they watch the bishops only ever moving diagonally then they are justified in believing that bishops only ever move diagonally, and if bishops only ever move diagonally then they know that bishops only ever moving diagonally.
  • Isaac
    10.3k


    if one has a true belief then one has ascertained that one's belief is true.

    The above is a meaningless tautology, yes?

    So the only thing added is the justification.

    Yet you say that it's not the justification which makes a belief true.
  • Michael
    15.4k
    if one has a true belief then one has ascertained that one's belief is true.

    The above is a meaningless tautology, yes?

    So the only thing added is the justification.

    Yet you say that it's not the justification which makes a belief true.
    Isaac

    Justification isn't what makes a belief true, it's what makes a true belief count as knowledge (as opposed to a lucky guess).
  • Isaac
    10.3k


    OK, so

    1. if one has a justified true belief then one has ascertained that one's belief is true

    2. if one has a justified true belief then one has ascertained that one's belief is true

    You're saying that 1 is false, but 2 is just a tautology.

    So the question of how one ascertains whether one's belief is true, other than by justificatory beliefs, seems to remain unanswered.
  • Michael
    15.4k
    OK, so

    1. if one has a justified true belief then one has ascertained that one's belief is true

    2. if one has a justified true belief then one has ascertained that one's belief is true

    You're saying that 1 is false, but 2 is just a tautology.
    Isaac

    I'm saying:

    3) if one has a justified true belief then one has ascertained that one's belief is true
  • I like sushi
    4.8k
    So it is a justified belief NOT a justified true belief (it cannot be as they are never privy to the exact rules of some said game).

    The 'game' in question here is reality at large too. None of us know the rules or limits. JTB only has scope within set parameters NOT in reality as it fails to distinguish where the borders of use are and is an attempt to use abstraction in reality as some absolute rule declaring what is or is not truth (but such truths are subject to change depending on the community and subjective intents).
  • Michael
    15.4k
    So it is a justified belief NOT a justified true beliefI like sushi

    No, it's a justified true belief. Obviously if bishops can actually move vertically as well then they don't know the rules of the game.
  • Isaac
    10.3k
    I'm saying:

    3) if one has a justified true belief then one has ascertained that one's belief is true
    Michael

    But...

    if one has a justified true belief then one has ascertained that one's belief is true.

    ...unarguably.

    So what's 'justified' doing?
  • Michael
    15.4k
    But...

    if one has a justified true belief then one has ascertained that one's belief is true.

    ...unarguably.
    Isaac

    It is arguable. If you had toast for breakfast this morning and if I believe that you had toast for breakfast this morning, it would be false to say that I have ascertained that my belief is true. I require justification for that. I need to have seen you eat toast this morning.
  • I like sushi
    4.8k
    And do we know the rules of the game of life? Chess is an abstracted and bounded category not an unknown quantity. There is a difference between abstracted truth and applying truth to reality right?
  • Isaac
    10.3k


    How would you ascertain I had toast for breakfast, other than by your justifications for believing I had toast for breakfast?
  • Michael
    15.4k
    And do we know the rules of the game of life? Chess is an abstracted and bounded category not an unknown quantity. There is a difference between abstracted truth and applying truth to reality right?I like sushi

    I honestly don't know what you're saying any more. Your original claim was that the JTB definition of knowledge entails that flat-Earthers have knowledge that the Earth is flat. I am simply arguing that it doesn't. I am arguing that 1) they only have knowledge if the Earth is in fact flat, and 2) the Earth isn't flat and so they don't have knowledge.

    If you want to argue that I can't be certain about 2) then that misses the point. 1) is the relevant counter-claim. Knowledge, according to JTB, requires more than just a justified belief; it requires that the justified belief is true.
  • Michael
    15.4k
    How would you ascertain I had toast for breakfast, other than by your justifications for believing I had toast for breakfast,Isaac

    1. if you had toast this morning and if I saw you eat toast this morning and if I believe that you had toast this morning then I have ascertained that you had toast this morning

    2. if you didn't have toast this morning and if I saw you eat toast this morning and if I believe that you had toast this morning then I haven't ascertained that you had toast this morning

    3. if you had toast this morning and if I didn't see you eat toast this morning and if I believe that you had toast this morning then I haven't ascertained that you had toast this morning

    I have ascertained that X is true if 1) X is true, 2) I believe that X is true, and 3) I have justified in believing that X is true.
  • Isaac
    10.3k
    Knowledge, according to JTB, requires more than just a justified belief; it requires that the justified belief is true.Michael

    Then the JTB account is clearly wrong because we use the term 'knowledge' all the time and yet can never ascertain that the beliefs therein are 'true' by means other than justifications.
  • sime
    1.1k
    John knows that it is raining if:

    1) John believes that it is raining,
    2) John is justified in believing that it is raining, and
    3) it is raining

    It would be a mistake to interpret this as saying that John knows that it is raining if:

    1) John believes that it is raining,
    2) John is justified in believing that it is raining, and
    3) I believe that it is raining

    This latter argument is obviously fallacious.
    Michael


    If 3) refers to your belief that it is raining, then I would say, by appealing to the meaningless of Moore's Sentence, that :

    John doesn't know that it is raining from my perspective,
    John knows that it is raining from your perspective.

    If this looks uncomfortable, recall as Wittgenstein did, that we often say "I thought I knew, but i am proven wrong". From the perspective of ordinary language philosophy, the use of the verb "to know" doesn't imply infallibility of belief.

    Consider also:-

    1) John is blind, never leaves the house, and believes that it is raining,
    2) John is justified in believing that it is raining, and
    3) you and I directly observe that it isn't raining.

    In which case John's belief that it is raining is false-according-to-us. But if we are privy to "insider information" about the weather that John does not and cannot possess, then is it logically coherent for us to interpret John's concept of the weather as being the same as ours?

    If John's justification for his beliefs is logically valid and logically sound with respect to information he possesses, and if he is never confronted with a situation in which he declares his previous beliefs to be wrong, then where is John's mistake?
  • Isaac
    10.3k


    I asked how you ascertain whether I had toast this morning and your answer requires that you first know whether I had toast this morning. Try answering again but without the contingency 'if you had toast this morning'. That is yet to be ascertained so cannot form part of our method for ascertaining.
  • Michael
    15.4k
    If 3) refers to your belief that it is rainingsime

    It doesn't. It refers to the independent fact that it is raining.
  • Michael
    15.4k
    I asked how you ascertain whether I had toast this morning and your answer requires that you first know whether I had toast this morning.Isaac

    No it doesn't.

    Michael has ascertained that Issac had toast this morning if 1) it is an independent fact that Issac had toast this morning, 2) Michael has seen that Issac had toast this morning, and 3) Michael believes that Issac had toast this morning

    I don't need to first know that 1) is true. 1) just needs to be true, independent of what I believe. Then, assuming I believe 1) and am justified in doing so, it then follows that I know 1).
  • sime
    1.1k
    It doesn't. It refers to the independent fact that it is raining.Michael

    An independent fact according to whom?
  • Michael
    15.4k
    An independent fact according to whom?sime

    It's not according to anyone. It's about what really is the case, irrespective of what anyone believes.
  • sime
    1.1k
    It's not according to anyone. It's about what really is the case, irrespective of what anyone believes.Michael

    So according to us? See my last example.
  • Michael
    15.4k
    So according to us?sime

    No, not according to us. It's not according to anyone. It's about what actually is the case. I don't understand what's difficult about this.
  • Isaac
    10.3k
    it is an independent fact thatMichael

    But since you cannot ascertain whether it is an independent fact that I had toast this morning (by your own admission), your claim 'l know you had toast this morning' is always, forever undeterminable. It it contingent on a fact that can never be established. So how is it any different from 'I believe you had toast this morning'? All it tells me, the act of communication, is that you believe I had toast this morning. It tells me nothing different to 'I believe you had toast this morning'.
  • Michael
    15.4k
    But since you cannot ascertain whether it is an independent factIsaac

    You can, that's what the justification does. If you have justification that X is true, and if X is true, then you have ascertained that X is true.
  • sime
    1.1k
    No, not according to us. It's not according to anyone. It's about what actually is the case. I don't understand what's difficult about this.Michael

    Every assertion has a cause. In your view, is it possible to grasp the meaning of an assertion without understanding the cause of the assertion?
  • Michael
    15.4k
    In your view, is it possible to grasp the meaning of an assertion without understanding the cause of the assertion?sime

    Yes. The meaning of a proposition is one thing, the motivation for a speech act is another. The latter is irrelevant for this discussion.

    Just because my assertion "you're a fucking twat" implies that I dislike the person I'm speaking too, and that I am an uncouth person, it doesn't then follow that "you're a fucking twat" means "I dislike you and I am an uncouth person."

    Just because my assertion "it is raining" implies that I believe that it is raining, it doesn't then follow that "it is raining" means "I believe that it is raining."
  • sime
    1.1k
    Just because my assertion "it is raining" implies that I believe that it is raining, it doesn't then follow that "it is raining" means "I believe that it is raining."Michael

    If you say "It is raining", i cannot interpret you as saying anything other than " Michael believes it is raining".

    And if i notice that it isn't raining, then it begs the question as to how a false state of affairs could cause your belief. The notion that the cause of a belief can be detached from the intentional object of the belief is a fallacy, well, at least according to me.
bold
italic
underline
strike
code
quote
ulist
image
url
mention
reveal
youtube
tweet
Add a Comment

Welcome to The Philosophy Forum!

Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.