• TheMadFool
    13.9k
    Knowledge: Justified True Belief (JTB)

    S knows P IFF
    1. S believes P
    2. P is justified
    3. P is true

    It's dusk, you're a farmer. You go into your fields and see a cowish shape (it actually happens to be a cloth swaying in the wind). You conclude that there's a cow in your field. There, in fact, is a cow in your field.

    P = There's a cow in your field.

    S = You.

    Justification for P = the cowishly shaped cloth.

    You are justified in believing there's a cow in your field, you believe there's a cow in your field, and there is a cow in your field.

    All conditions for knowledge are satisfied but then you got it right by fluke: a cow happened to be in your field.

    Issue/problem: The scope of the inference is in excess of the evidence. The correct inference you should've made is that cowishly shaped cloth is a cow (false) and not that there's a cow in your field (true).

    Are all Gettier problems fallacious: do the conclusions go beyond what the evidence actually supports?
  • Michael
    11.8k
    If one can infer B from A and if B entails C then one can infer C from A.

    If the cowishly shaped cloth is a cow then there is a cow in my field, therefore if I can infer that the cowishly shaped cloth is a cow given the evidence then I can infer that there is a cow in my field given the evidence.
  • tim wood
    8.4k
    I know how to whittle wood. I conclude this on the basis of evidence. The evidence is that from time to time I whittle wood. Anyone notice what just happened? There is knowledge and experience involved in whittling wood. What does any of it have to do with justification, true, or belief? (And what exactly are justified, true, and belief ? No discussion of these getting anywhere without adequate definitions/understandings of these terms.)

    It would appear there are at least two sorts of knowledge, knowledge how and knowledge that. (Also knowledge about - but what is knowledge about about?) With - using - the knowledge how to whittle wood, I whittle wood. But the knowledge that I know how to whittle wood will never ever get any wood whittled, and indeed has nothing to do with whittling wood.

    And what exactly is the knowledge that I can whittle wood? Whatever it is, it is not and cannot be commensurate with the knowledge of how to whittle wood. It appears that knowledge how is the same as having a skill, while knowledge that is just a kind of bet that the bettor expects to win - hence "knowledge" - but could also lose.

    Hillary Hahn knows how to play the violin. I too know how to play the violin. Hmmm.
  • unenlightened
    7.1k
    2. P is justifiedTheMadFool

    Justification is not an on off thing, one can have more or less of it. The storyteller has more justification than the farmer because the storyteller 'knows' that the cow shape is a cloth. Story-tellers always know better than their characters because they are the god of the story.

    One can see that justification is also knowledge, and that one can be wrong when one thinks one knows something. So the farmer is mistaken in his implicit claim to know that a that a cow shape is a cow. Had he further justified this by touch or smell, he would not have made the knowledge claim about the cow in the field.

    Gettier is mistaken in thinking he has found a failure in our understanding of knowledge. He has discovered fallibility.
  • Michael
    11.8k
    One can see that justification is also knowledge, and that one can be wrong when one thinks one knows something. So the farmer is mistaken in his implicit claim to know that a that a cow shape is a cow. Had he further justified this by touch or smell, he would not have made the knowledge claim about the cow in the field.

    Gettier is mistaken in thinking he has found a failure in our understanding of knowledge. He has discovered fallibility.
    unenlightened

    Not sure what you're trying to say here. Are you saying that the farmer's belief isn't justified?
  • unenlightened
    7.1k
    Are you saying that the farmer's belief isn't justified?Michael

    Yes. It is justified by something that turns out to be false, so it it turns out not to be justified. this is how we proceed is it not? Then it turns out to be true anyway, but so what?Farmer Giles believes his cabbages will fail because the fairies have cursed them and that belief is justified on the grounds that he failed to put milk out for them last full moon. Turns out that the milk would have attracted hedgehogs who would have eaten the slugs that are the real villains of the story. Farmer Giles is right in predicting the failure of the cabbages, but this is not then evidence for the existence of fairies.
  • TheMadFool
    13.9k
    I've gone over this issue with another poster who, very insightfully, raised the issue of knowing how to cycle in another thread on epistemology. Does the cerebellum (motor skills) know in the same sense as the cerebrum (thinking skills)? I pointed out that motor skills can be broken down into a set of propositions (cerebrum-apt) and so yeah, knowing how to whittle is, in some sense, a justified true belief.

    Intriguingly, Martin Rees claims that Newton's laws are physically hardwired in our brains. How else do we make good estimates on what we can handle, physically, and what we can't. Just sayin'.

    Where do we go from here?

    Gettier is mistaken in thinking he has found a failure in our understanding of knowledge.unenlightened

    I agree.

    He has discovered fallibility.unenlightened

    Yup.

    What I'm driving at is all Gettier cases seem to be such that they violate the proportio divina rule (the conclusion is disproportionate given the premises).

    Gracias for the input.
  • Michael
    11.8k
    Yes. It is justified by something that turns out to be false, so it it turns out not to be justified. this is how we proceed is it not?unenlightened

    A false belief can be justified. That's why the JTB definition of knowledge is JTB, not just JB.

    Farmer Giles believes his cabbages will fail because the fairies have cursed them and that belief is justified on the grounds that he failed to put milk out for them last full moon.

    Not having put out milk last full moon doesn't justify a belief that fairies exist and cursed his cabbages.

    Whereas seeing something that looks like a cow in his field may justify his belief that there is a cow in his field.
  • Michael
    11.8k
    What I'm driving at is all Gettier cases seem to be such that they violate the proportio divina rule (the conclusion is disproportionate given the premises).TheMadFool

    Let's say that you put 123 × 123 into a calculator and it tells you that the answer is 15,129. Are you justified in believing that 123 × 123 = 15,129?
  • TheMadFool
    13.9k
    Let's say that you put 123 × 123 into a calculator and it tells you that the answer is 15,129. Are you justified in believing that 123 × 123 = 15,129?Michael

    I believe I am (justified). The calculator nearly always gets basic math right. What's your point?
  • TheMadFool
    13.9k
    A false belief can be justified. That's why the JTB definition of knowledge is JTB, not just JB.Michael

    Justification is not sufficient for truth but I have a feeling that it's a necessary condition. Oh! Gödel.
  • Michael
    11.8k
    I believe I am (justified). The calculator nearly always gets basic math right. What's your point?TheMadFool

    What you didn't know is that the calculator you used is broken and always gives an answer of 15,129, regardless of the equation you enter.

    You believe that 123 × 123 = 15,129, it is true that 123 × 123 = 15,129, and as per your own acknowledgement you are justified in believing that 123 × 123 = 15,129. But Gettier would argue that you don't know that 123 × 123 = 15,129. Your justified belief is only accidentally correct.
  • TheMadFool
    13.9k
    What you didn't know is that the calculator you used is broken and always gives an answer of 15,129.

    You believe that 123 × 123 = 15,129, it is true that 123 × 123 = 15,129, and as per your own acknowledgement you are justified in believing that 123 × 123 = 15,129. But Gettier would argue that you don't know that 123 × 123 = 15,129. Your justified belief is only accidentally correct.
    Michael

    The standard response to that would be a presupposition was wrong. Gettier isn't right still. I'm not justified.
  • Michael
    11.8k
    The standard response to that would be a presupposition was wrong. Gettier isn't right still.TheMadFool

    Why isn't he right? You have a justified true belief but you don't have knowledge.
  • TheMadFool
    13.9k
    justifiedMichael

    Not justified. An assumption - the calculator is working - was false.
  • Michael
    11.8k
    Not justified. An assumption - the calculator is working - was false.TheMadFool

    You said it was justified.

    And as above, a false belief can be justified.
  • TheMadFool
    13.9k
    I guess the right way to claim knowledge is to put an "if" before it.

    IF all my assumptions are true then P is true.
  • TheMadFool
    13.9k
    You said it was justified.

    And as above, a false belief can be justified.
    Michael

    I change my mind.
  • Manuel
    3k
    As I see it, insisting on JTB forces an unnecessary constraint on what knowledge is. It can lead us to conclude that people who study ancient Mythology, pre-modern science and much common sense belief to not be knowledge at all.

    Heck, even all our current beliefs could turn out to be wrong, and we would know nothing.

    It's better to let go of this constraint and simply use the word knowledge as we tend to do in ordinary life, which usually does not pose much problems in discussion, outside of specific cases like this.

    But that's just me.
  • Michael
    11.8k
    If all my assumptions are true then P is true.TheMadFool

    But false beliefs can be justified, too. Again, that's why knowledge is commonly defined as justified true belief, not just justified belief.
  • TheMadFool
    13.9k
    But false beliefs can be justified, too. Again, that's why knowledge is commonly defined as justified true belief, not just justified belief.Michael

    Gimme an example of a false belief that's justified. Inductive arguments are not allowed.
  • Michael
    11.8k
    Gimme an example of a false belief that's justified. Inductive arguments are not allowed.TheMadFool

    I use a calculator and it tells me that the square root of 2 is 1.41421356237.
  • I like sushi
    4k
    Your belief that Gettier is wrong :razz:
  • TheMadFool
    13.9k
    I use a calculator and it tells me that the square root of 2 is 1.41421356237Michael

    This is unjustified. We've already crossed that bridge.
  • TheMadFool
    13.9k
    Your belief that Gettier is wrong :razz:I like sushi

    :smirk:
  • Michael
    11.8k
    This is unjustified. We've already crossed that bridge.TheMadFool

    You're working from a very different understanding of justification, then. One contrary to proponents of the justified true belief account of knowledge.

    The very fact that they propose that knowledge is justified true belief and not just justified belief is proof that they understand that false beliefs can be justified, too.

    Gettier is arguing against what they mean by a belief being justified, not against whatever you mean.
  • TheMadFool
    13.9k
    To All

    Justification is just another word for argument. A deductive argument is such that if it's valid and the premises are true (sound argument), the conclusion has to be true.

    Under the JTB definition of knowledge, insofar as deduction is concerned, the condition true is redundant.
  • TheMadFool
    13.9k
    Please read above.
  • Michael
    11.8k
    The JTB definition of knowledge, insofar as deduction is concerned, has the condition true as redundant.TheMadFool

    According to what you mean by "justified". But that's not the meaning of "justified" as used by those who argue(d) that knowledge is justified true belief, and so not the meaning of "justified" as used by Gettier.
  • TheMadFool
    13.9k
    According to what you mean by "justified". But that's not the meaning of "justified" as used by those who argue(d) that knowledge is justified true belief, and so not the meaning of "justified" as used by Gettier.Michael

    What is Gettier's definition of "justification"? I'm curious.
  • Michael
    11.8k
    The standard, common sense understanding. If a calculator tells me that the answer to 123 × 123 = 15,129 then I am justified in believing that 123 × 123 = 15,129. If I tell you that my name is Michael then you are justified in believing that my name is Michael. If all the experimental data of the time supported Newton's law of universal gravitation then the people of the time were justified in believing Newton's law of universal gravitation.
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