Talk:Gettier problem

Article status December 2003
Good job, Radgeek!

In the formulation of the JTB account, I provided internal links for the philosophical terms occurring for the first time in this article. I don't know what to do with "evidentially justified". Currently there is no article about evidence in philosophy (there should be, of course), and in the article "Theory of justification" evidence (or evidential justification) is not mentioned. Does "evidentially justified" here mean the same as "epistemically justified"? Andres 11:44, 9 Dec 2003 (UTC)

Goldman's theory is discussed also in the article "Reliabilism". I think there should be an article "Causal account of knowledge" or "Causal theory of knowledge" (as that article proposes).

In this article, I miss a bit more explanations about Goldman's account. What examples does he bear in mind when he talks about "inappropriate" causality? How exactly does reliabilism help? Andres 13:25, 9 Dec 2003 (UTC)

Thanks, Andres, for your kind words about my submissions, and for your revisions today. I'm using "evidentially justified" here to mean the same thing as "epistemically justified" Thus, "evidence" is being used here in a sense that's weak the the point of redundancy--it's whatever sort of stuff counts toward justifying or warranting a belief. I mainly included the phrase as a way of pointing out to beginning readers, what may not be immediately obvious, how "justification" is being used by epistemologists who are concerned with it. I think "evidentially justified" is the best way to get at the point without throwing on tags of episte-this, -that, and -theother. But it does indicate a certain bias towards aposteriori empirical justifications that I wish it didn't indicate. Perhaps there is a better locution; or perhaps we should just turn the issue over to an entry on "evidence" which could make the proper distinctions between stronger and weaker senses of the term.

- R.G. 10:18 EST, 9 Dec 2003


 * I had an eye on the article Theory of justification. It does mention evidence as one type of justifier. This article requires a lot of work to be done on it. I think the appropriate title should be "Justification (epistemology)". So when we have such an article I would like to link "justified" to that article instead of "Theory of justification". It would begin from explaining how is an epistemic justification of a belief different from a moral justification or a prudential justification of a belief.


 * I share your point that the presentation should be clear for the beginner. Probably "evidentially" makes more or less clear what kind of justification is meant, though it could be misread to be a technical term. I think that the best solution is keep the word "evidentially" for time being; and when the article "Justification (philosophy)" is there then substitute "epistemically justified" to that article. In that case anyone would feel that this is a technical term, and would follow the link if she doesn't know what mean. So at least she would avoid misunderstanding. Andres 16:42, 9 Dec 2003 (UTC)

I agree with Andres that there ought to be another essay on "causal theory of knowledge." Indeed, we would probably benefit from a cluster of "causal theory of..." pages, given the importance of causal theories of meaning, perception, etc. over the past couple decades. I also would like to see more explanation on Goldman and causal responses (both their assets and their liabilities), but I'm somewhat tentative because, while I know a bit about the Gettier problem, I don't know *that* much about causalist responses to it. I'd hope that I might be able to defer to someone more knowledgeable than I about filling in the details. (One particularly vexing detail is that causalist accounts tend to be particularly hard to classify. Sometimes they seem to read like JTB+G accounts looking for a fourth condition; sometimes they seem to chuck out the J condition and replace it with a new condition; and sometimes they seem to be saying that causal requirements are part of a properly externalist J condition. I -think- Goldman leans towards the third option more than the first or second; but I've also seen him widely read as taking the first, and I'm not familiar enough with his work to strongly say one way or the other. Additionally, it looks like even if he does take the third requirement, he also has an additional requirement of 'correct reconstruction' that he wants to add on--so what to say? In any case, other causalists/reliabilists seem to take different stances towards how exactly to classify themselves.)


 * I remember this problem well from Philosophy 101. I will never understand why it is not obvious to everyone that the person in this scenario IS NOT JUSTIFIED in holding their belief; they just happen to be right. Steve (talk) 07:07, 28 September 2014 (UTC)

In any case, the typical examples of "inappropriate" sorts of causality are cases where a fact is involved in a particular perception or belief, but where the causal chain runs in such a way that we are inclined to classify it as a hallucination or a delusion. For example, suppose that Fred has a psychosis, which causes him to falsely believe that he is Caligula. Fred knows a lot about Caligula, including the fact that Caligula was psychotic; and since Fred believes that he is Caligula, he believes that he has a psychosis. This looks like a perfectly good causal chain from the fact that Fred has a psychosis to his belief that he does. But I doubt that we could call Fred's belief an instance of self-knowledge--rather, it's a very peculiar sort of delusion. (It's peculiar because it's one that happens, by accident, to be true.)

Or consider the boy who cried wolf: the fact that he saw a wolf caused him to tell the villagers that there was a wolf there. And when he told the villagers that there was a wolf there, this may have caused some of them to believe it, at least until they stopped to think. But the problem with the little boy who cried wolf was that he was a habitual liar--and so the villagers realized that they would hardly be justified in believing him. Even though he happened to be telling the truth that specific time, the point of the tale seems to be that there's no reasonable way that we could have expected the villagers to treat what he told them as knowledge, even after they had found out the truth.

I hope this helps make clearer what Goldman's concerned with in trying to specify the right kinds of causal chains. Reliabilism is supposed to resolve these problems by endorsing any causal chain that -reliably- produces true beliefs. The problem with testimony from the little boy who cried wolf is that he's an unreliable source; but we might be justified in believing someone who reliably told the truth, and the testimony of our senses has, ostensibly, evolved to be reliable by and large and for the most part. I am of the opinion that reliabilism doesn't actually solve the problems that it sets out to solve, and that there are a number of problems with, for example, knowledge by testimony that require a great deal more of what might seem like naive faith than reliabilism allows for. Whatever the case, though, I don't know immediately how best to integrate this material into the article--but all should feel free to make any or no use of it themselves, according to their use for it.

- R.G. 15:44 9 Dec 2003 UTC


 * Thank you for your explanations. They are helpful. Currently I am going through Goldman's article (1967). It can be found here. Andres 17:02, 9 Dec 2003 (UTC)

One other quick note on how reliabilist causal accounts try to solve the Gettier problem. The idea here is that the reason the Gettier cases trouble us is that their beliefs are formed, in some sense, accidentally--that is, they are either not caused by the facts, or caused by the wrong facts, or caused by the facts in the wrong way. Thus, for example, when Smith formed his belief that the man who gets the job will have ten coins in his pocket, he happened to be right--but he would have formed that belief anyway, even if Smith had actually had 24 coins, or no coins, in his pockets, because Smith was mistaken to think that Jones would be the man who got the job. That is to say, Smith would have formed the same belief even if it were false.

The answer is not quite so straightforward when it comes to Fred-who-thinks-he's-Caligula. One of the peculiar features of Fred's belief is that he wouldn't have formed the same belief if it were false (he couldn't think he was Caligula if he didn't have a psychosis of some kind). But there still seems like there's an important sense in which the connection between his belief and the facts is accidental... the same sense, perhaps, in which it seems clear that "having a color" and "having a shape" are not the same property, even though everything which has a color also has a shape. One way to explain this is by appealing to the fact that the beliefs of a psychotic are not a reliable guide to truth (although most psychotics may very well not know this), because the mark of psychosis is the formation of beliefs without regard to whether they are true or false. To pull a distinction from action theory, Fred's psychosis may be a cause for his belief that he has a psychosis, but it isn't one a reason.

(Fred may, incidentally, be a fairly decisive counter-example for Nozick's counterfactual account. The nearest possible world in which Fred does not have a psychosis is one in which he does not believe that he has a psychosis, since it's one in which he does not believe that he is Caligula. But I suppose that Nozick may be able to throw his second counterfactual at it--the sphere of the nearby possible worlds in which it is true that Fred has a psychosis includes the actual world where he believes that he does, but it may also be argued that he could just as easily have thought that he was Napoleon, or Jesus, or George Washington--and in those worlds he might very well not believe that he has a psychosis. In that case, the strict counterfactual would fail.)

- R.G. 16:10 9 Dec 2003 UTC

Another issue. It is put in the article that Gettier's problem is somehow the hard problem of contemporary epistemology. I consider putting it that somehow that problem stimulated the whole development of contemporary analytical philosophy. Would it be true? In any case, there are epistemologists (such as Pollock) who think that Gettier's problem is peripheral in epistemology. Andres 17:02, 9 Dec 2003 (UTC)

I want to notice that there are other articles with similar stuff: Edmund Gettier, justified true belief, knowledge (philosophy), epistemology. I don't think that redundancy is bad. However, we should have an informed choice about where to put our material. Andres 17:02, 9 Dec 2003 (UTC)

About responses to the Gettier problem - what about fallibilism? Methinks it deserves a mention. --AceMyth 05:32, May 18, 2005 (UTC)

Ah, Radgeek. I'm the guy who edited the "no false lemmas" solution section. I'm sorry I was wrong in doing so. I'm unfortionatly just taking my second philosophy class, first time studying knowledge, and as I was going through this I thought i'd edit it. I don't personally see how "Jones is in the room" can be viewed as non-inferential, however i'll take your word on it. As for the example I talked about... I did not want to post it because it is not my own, it was written by some guy who i'm sure has copyright over it, or something, but it goes like this:

Jones in Smith work in the same office building with several other people. Jones tells Smith that he owns a ford, shows him a certificate to prove as such, has always been very reliable in the past, etc.

Smith forms the premise: Jones told me that he owns a ford, showed me a certificate to prove as such, has always been very reliable in the past, etc. Then he infers: Someone in the office told me he owns a ford, showed me a certificate to prove as such, has always been very reliable in the past, etc. Then he infers: Someone in the office owns a ford.

Well, as typical of the Gettier problem, Jones is a liar, and he does not own a ford. However, another person in the office, David, does own a ford, and thus his conclusion was true.

I didn't write it. It's paraphrased, and poorly at that. Anyway, do what you can we that, and I am sorry for the inconvenience.

Since nobody responded I went ahead and added the basic facts about fallibilism as a response to the Gettier problem. Contribution/merciless editing is welcome. --AceMyth 04:09, August 30, 2005 (UTC)

The section on Goldman is really hard to undersatand, it's hard to see how James Chase applies to Goldmans reliabilism. Any evidence of someones death, ought to be able to work as a true belief causing the truth in the appropriate way, not just the acctual cause of death. It needs to be explained, either why it's not according to Goldman, or why the counter example is valid. And by the way who is this Mr. Chase, the article links to some republican, that is highly unlikely to have said anything about Goldman, as the latter was seven years old one James died.Ttias (talk) 09:26, 19 November 2008 (UTC)

This page illustrates the weakness of Wikipedia. The original page, if uninspiring in someways, was at least 'efficient' Over time, the page has become along and rambling discourse. It has in many ways lost it sfunctionas an encylopdia article, and become more like a series of term papers for philosophy class! But who wil jude what is 'justifed' and 'necessry' here?

Dremeraldgibb (talk) 14:27, 31 May 2008 (UTC)

Gender bending
Is it really necessary that both Smith and Jones change in gender between the first two examples and the third? It just confused me. I'll make the switch but if there is a genuine reason why the gender change takes place... IDX 15:18, 17 May 2007 (UTC)

Recent change
The following was just added to the section of the article presenting objections to the "no false lemmas" solution, after the case in which Smith rightly believes that Jones is in the room after mistaking a Jones-shaped mannequin in the room for Jones:


 * This counter-example fails to disprove the "no false premises" solution, however, because "Jones is in the room" is not non-inferential but was inferred from a false premise, "I see Jones." Other Gettier-style problems exist, however, which do succesfully disprove this solution.

The addition is doubly unfortunate. First because it's tendentious: lots of philosophers do not regard a belief like "Jones is in the room" to be inferred from "I see Jones in the room"; if you think "Jones is in the room" is (part of) the content of the perception, and that the deliverances of perception are direct (non-inferential), then the belief "Jones is in the room" isn't being inferred from anything. Of course, some philosophers don't think of perception that way, either; but confidently describing the example as another case of inference is begging the question against the philosophers who would advance a case like this against the "no false lemmas" solution in the first place.

Secondly, there may well be better cases, but just mentioning that they exist isn't much help. If there's an example better than the mannequin case I know that I for one would be glad to hear it, but just issuing a promissory note for it isn't much help.

I've just deleted the material that was posted. I'm sorry to just revert, but unless a better example is actually supplied this material just isn't any help at all.

So-called Gettier "Problem"
I just wanted to add my opinion here that ever since the Gettier Problem was presented to me in my Epistemology course in undergraduate philosophy back in 1994, I've always thought that the so-called "Gettier Problem" is flawed; there is no problem.

Most Gettier-type-problems (like Gettier's case 1) typically conflate the sense-reference distinction. The flaw is that the element of "true" in the "justified, true belief" formula is typically missing because the referent of belief shifts in these sorts of "problems". Take Gettier's case 1: the referent of "the man" is always Jones, not Smith. Thus, Smith never knows because his belief is false, not true. Basically most Gettier problems equivocate about the referent by using an ambiguous term like, as in Gettier's case 1, "the man".

Gettier's case 2 is flawed in a more complicated manner. One of the problems is that it implicitly, but incorrectly, presumes that "justification" is transitive across a disjunction; there is no transitivity of justification: while Smith may be justified in believing "Jones owns a Ford", that does not give Smith justification from "Jones owns a Ford" to either "Brown is in Barcelona" OR "Jones owns a Ford or Brown is in Barcelona". Another way of stating this is that justification must be associated with the referent. In this case the justification is incorrectly imputed from 1 referent to 2 referents (that referent plus another referent). But the flaw goes deeper, IMO, in that the traditional "justified, true belief" formulation taken from Plato goes too far. As Crispin Sartwell has asserted: Knowledge is simply "true belief"...nothing more, nothing less: epistemic minimalism. It doesn't matter what reason or lack of reason for believing P .... if a person believes P and P is true, then that person knows P. What should be taken from Plato is not that every true, belief must be "justified" to count as knowledge, but rather the understanding that there is a spectrum of knowledge with "weak knowledge" at one end of the spectrum and "strong knowledge" at the other end of the spectrum. "Weak knowledge" would be randomly believing P and just being lucky that P is true. "Strong knowledge" would be something like a "justified, true belief that is conclusively established once and for all". Now any good philosopher would agree that "strong knowledge" is not obtainable by a mere human...a god or otherwise omniscient being, yes, but not a mere human. The only issue left is, what counts for "justification"? What theory? Foundationalism? Reliablism? Coherentism? The answer is yes. A true, belief that has more grounds for being justified will be further along the spectrum towards "strong knowledge" than a random, non-justified, true belief.


 * I believe that some of the early efforts to answer Gettier turned on the transitivity argument. But ... Gettier-like cases were soon produced to which it wasn't pertinent. See Gail Stine, for example, in "Skepticism, Relevant Alternatives and Deductive Closure," Philosophical Studies, (1976). Suppose John is driving through the countryside and sees a lot of barns. Or at least they look like barns, and the rural area is just the sort that often has barns. Ordinarily, we wouldn't ask for more -- John knows that those are barns. But they aren't ... the people of this area long ago adopted the practice of constructing paper-mache facades to fool passers by. So John doesn't have knowledge for the simple reason that his belief is false. Okay, a little while later, John learns about this eccentric pseudo-farming, neighborhood, has a good laugh about the trickery, and drives through it again. In the meantime, somebody actually has built some real barns amid the facades, but it isn't at all obvious to drivers-by which is which. John doesn't know this, and thinks its all still facades (always one step behind, poor John). On this drive, he passes a particular structure, says, "that's an especially realistic facade of a barn," and he happens to be right, but could just as well have been wrong, it might have been one of the newer real barns. Gettier, and I think most contemporary philosophers with him, would say that this isn't knowledge, although its a justified true belief. And the issue of transitivity isn't present at all. John is pointing at a particular object when he utters the words, that object is what he thinks it is, he has reasons to believe that it is, but other considerations make us see those reasosn as unconnected to his conclusion, and so defeat the claim of knowledge. Such, at any rate, is the view of Professor Stine. --Christofurio 20:48, September 10, 2005 (UTC)

Counterexample
Counterexample is a perfectly legitimate means of ruling something out. In this case Gettier's counterexamples rule out the JTB notion. --172.199.93.84 19:55, 20 October 2005 (UTC)


 * You're currently banned from editing outside your case. You're kidding yourself if you think I'm going to have a discussion with you. Rhobite 20:40, 20 October 2005 (UTC)


 * WP:NPOV --causa sui talk 20:25, 21 October 2005 (UTC)

Fallibilism
Nathan Ladd recently reverted a comment I added to clarify the Kirkham section. What I said is that Gettier's objections constitute a mild skepticism, ruling out certainty but not all knowledge. In other words, it endorses fallibilism. Ladd disagreed, but did not explain why. This is his chance to do so. Alienus 09:13, 15 December 2005 (UTC)


 * First of all, it was Kirkham, not Gettier, to whom you attributed fallabilism whether you intended to or not. If you think Gettier endorses fallabilism, and you can cite a published source that also thinks so, then put that in some part of the article other than the section on Kirkham. (Note: You have to cite a source because if it is only you that thinks so, then your view would constitute "original research" which is not allowed.)

As for Kirkham, he does not endorse the view that there are senses of "know" in which one can have knowledge that is less than certain. Quite the contrary, his point is that the Gettier problem refutes this claim. The Gettier problem shows that knowledge requires evidence that necessitates the belief. And this, in turn, as he is at pains to point out, implies a very sweeping skepticism. He also believes that being rational does not require having knowledge; that is, you can be rational in believing P even if you don't know that P. But that view is not fallabilism by any definition I've heard. Kirkham is one of those philosophers, like Richard Foley, who separates the conceptual domain of "rationality" and closely related terms from the conceptual domain of "knowledge" and "justification". --Nate Ladd 03:41, 16 December 2005 (UTC)


 * Thanks for responding. My intention was indeed to attribute fallibilism to Gettier, not Kirkham.  I made the attribution in the Kirkham section as a clarification of the implications of Kirkham's interpretation of Gettier.


 * Now, as to what I meant, I'll explain briefly. Gettier's problem not only attacks the JTB definition, but also the notion that we can know whether a belief constitutes knowledge. For example, a belief may well be true and justified but the justification is coincidental to the truth, hence the belief is not knowledge. Unless we can rule out this possibility, and it's unclear how we might do so even in principle, Gettier is setting a limit to our knowledge about knowledge, hence to knowledge in general. In this way, a consequence is some form of fallibilism or even skepticism.


 * In any case, rather than further disputing this with you, I'll accept the revert for now and address this issue at a later date, when I have more time to research citations. Alienus 22:09, 16 December 2005 (UTC)

Article Title Choice
Why is this article named the Gettier 'problem'? Wouldn't "theorum" or "proposition" be more accurate? This may seem like nitpicking, but referring to this proposition as a problem presupposes a conclusion for which this is an obstacle. If Gettier called this a 'problem', then the title may be appropriate. Is this the case? --Heyitspeter 22:48, 18 December 2006 (UTC)
 * That's what they're called in the literature. As for your suggestions, a proposition is that which has a truth value. A theorem is a mathematical or (formal) logical proposition proved from some starting assumptions. A Gettier problem, on the other hand is a vignette that serves as a counterexample to the thesis that justified, true belief is knowledge. It's not a proposition of any sort. Simões ( talk/contribs ) 23:08, 18 December 2006 (UTC)
 * I agree with your assessment, but I understand Heyitspeter's confusion; take a look at the first sentence of the article, and I think you'll understand it, too. The article's lead text really needs to be rewritten to accord with the normal sense of the phrase "Gettier problem". —RuakhTALK 00:39, 19 December 2006 (UTC)

Responses to Gettier problem (see also other articles which discuss Gettier problems)
I posted the following on the talk page for Epistemology, but since there are multiple articles that refer to Gettier, and there is a merger proposal as well, is it appropriate in this occasion to repost same here? Referring to Gettier problems,

Surely Gettier must distinguish in some way between the following cases ;

I know I had ten coins in my pocket yesterday (I counted them).

I know I have ten coins in my pocket today (I counted them).

I know I will have ten coins in my pocket tomorrow (I can't possibly have counted them so I am guessing, not knowing).

I am making a FORECAST that I will have ten coins in my pocket tomorrow ( so I am guessing, not knowing).

Given that each statement suffers in at least some way from verifiabilty worries, is it still not so that the hallmark of scientific method is that experiments must be carried out before conclusions are drawn. So, on what basis one could one be tricked into thinking that a prediction about the future has the same evidentiary status as a conclusion drawn from the results of observations already made?Newbyguesses 23:51, 4 May 2007 (UTC)

Andres said - 9 Dec 2003

I want to notice that there are other articles with similar stuff: Edmund Gettier, justified true belief, knowledge (philosophy), epistemology. I don't think that redundancy is bad. However, we should have an informed choice about where to put our material. Andres 17:02, 9 Dec 2003 (UTC)

Has there been consolidation in these articles since then, or reconciliation of Gettier problems with Reliabilism, or what progress in the field in that time? What division of material is there between the articles? And is the merger proposal still on?Newbyguesses 13:20, 5 May 2007 (UTC)

Counterfactuals, thought experiment, counter-examples
Are they really counterexamples? (as in the lead sentence?). Thought experiment is better? And there are other words (I can not recall right now). Counterfactuals applies, but isn't quite the same thing? the cases (I), (II) are "speculative scenarios" or "word-plays" or "simulcrum scenarios", (That is, Smith is a fictional character.) How should this be expressed, as it brings into focus the distinct role played by the setter of the problem in asserting to Smith's statements. Any suggestions?Newbyguesses 06:12, 11 May 2007 (UTC)


 * All of these links have a bearing on the Gettier analysis, and in discussing exemplars such as case (I), the modes of speech (linguistics) are employed. Thus Epistemology,Epistemic modality, modes of speech, linguistics, as well as JTB, in discussing JTB, come into play. There is extensive literature, is there not, but I do not know where to find it at present and, it (imho) is quite pertinent. In discussing "justified true belief" encyclopediacally and comprehensively, these thinks perhaps should be considered as relevant, at least to look at.


 * I am not suggesting any or all links go in, nor where they go, since that is down to research. So, any additions I made, someone who has this page on the watchlist can lookat, and make any suggestions on Usertalk:Newbyguesses, please. I have no additions, deletions are fine, to make for now, as I said, ro did I? Some links need to go in?


 * I am enrolled in WikipediaProject:Philosophy, so I look forward to collaborateing would be nice.


 * Why would these links not be relevant?


 * In particular, what is the agency, what type of agency is assigned to Smith by the writer, and by us unconciously, in discussing,


 * of Smith, in believing, such and such?

Agent noun Human agency Rational agent Assertion is has particular entails Epistemic modality - judgement of confidence in belief Epistemic mood - indicates probability of utterence being true Evidentiality - in linguistics, indication of evidence existing ( a grammatical element) I hear that,i think that, it seems, it looks like reportedly" Pragmatics Pragmatism Foundations of mathematics Framing Has-a - computers Human agency human self-reflection language, Truth, and Logic(1936) - Alfred Ayer - Logical positivism - verification principle - sentence either verifiable or falsifiable Stipulative definition- this may be Law, but there are disambiguation pages too. Counterfactual conditional if that had been the case, then... if, what precisely is the status at any particular point in the discussion, of the counterfactualal conditional if which is pertaining to Smith''?
 * Agent (grammar)


 * Please, someone check my edits, I made a few, and I am new, so I will be not making any more for now, although I would like to see some links go in, or other suggestions. Sorry to talk so long, and some of the links I might get the markyup wrong, apologies, just try search at left of screen, under linguiistics and modes of speech ( a lot of Latin ones, but none, I think, in Law definitions do apply). Thankyou, now.Newbyguesses 08:00, 11 May 2007 (UTC)

case I and case II

 * It is my understanding (from wikireading only, I am not yet able to consult in the original and accompanying literature) that:


 * Gettier originally proposed case(s) I and II, substantially in these words?


 * Gettier has later refined these exemplars, in new words then?


 * The settings of these cases supplied presently in the article may appear somewhat perfunctory, it is not I think meant that the form of words be attributed as a quote to Gettier, but is it possible to identify where in the literature this particular set of words derives from? (or who claims to have written it, and make ensuing claims about JTB?).

Newbyguesses 20:20, 15 May 2007 (UTC)
 * My suggestion: that expansion of the article, researched (sourced) in the literature is required. There are numerous Philosophy articles impacted by this question, and as a very new contributer to wiki, I hope my suggestion will lead to improvement in these set of articles, by contribution from knowledgable persons via the talkpage. Please criticise my above conclusions if I have gone astray in this reasoning. I hope by posting here that my attention, and that of others, can be drawn to possibilites that enhance the Philosophy articles, which I must say, do present a wealth of interesting and informative reading.

the response to "no false premises"
"After arranging to meet with Mark for help with homework, Luke arrives at the appointed time and place. Walking into Mark's office Luke clearly sees Mark at his desk; Luke immediately forms the belief 'Mark is in the room. He can help me with my logic homework'. Luke is justified in his belief; he clearly sees Mark at his desk. In fact, it's not Mark that Luke saw; it was a marvelous hologram, perfect in every respect, giving the appearance of Mark diligently grading papers at his desk. Nevertheless, Mark is in the room; he is crouched under his desk reading Frege. Luke's belief that Mark is in the room is true (he is in the room, under his desk) and justified (Mark's hologram is giving the appearance of Mark hard at work)." is not a case with no false premises. At first, it looks like one. However, before Luke can form the belief "Mark is in the room", he must first form the belief "Mark is where I see him". This belief is false; therefore, the example fails. Is there a better example anyone can provide? Scythe33 (talk) 23:28, 17 December 2007 (UTC)
 * I agree. Actually - no one can give you any "better" example, because if there are no false premises and the logical steps are correct, then both the truth and the justification of the conclusion cannot be incorrect. The reason this whole "problem" got so much attention is way beyond me. The "No False Premises" approach seems correct, the only problem being with its definition of "knowledge" - it isn't feasible and even meaningless. Luke might as well have seen a living Mark, who acts and talks as mark, but "in truth" is actually a genetically-engineered copy. Give me a break. We would still call this "knowledge", because "no-false-premises-perfect-knowledge" is a meaningless concept. The difference between this case and the original "Mark" example, is the probability of the premise being true, and thats whats knowledge - as a socially defined word - is all about. Kirkham is correct, and there isn't really any problem left.
 * PavelR (talk) 22:58, 8 May 2008 (UTC)

Can anybody understand this sentence?
The grammar in the following sentence from the article is so bad that I cannot actually understand it: "Therefore, justified true belief may be defined singly is a problematical proposition presently, or that be the purpose of Gettier's theses to confound." If someone can make out what the meaning of this sentence is please fix it and reinsert it into the article, but I am going to remove it for the time being. b4hand (talk) 14:42, 19 July 2008 (UTC)

Grandma Case
The article mentions a "Grandma Case," but there is no further information given anywhere as to what the "Grandma Case" is, which is likely to confuse readers (including me). —Preceding unsigned comment added by 75.35.93.22 (talk) 02:36, 15 January 2009 (UTC)


 * I was also confused. I think this might be a reference to Tom's grandmother, as described here: http://www.niu.edu/~gpynn/311_H3.pdf "Tom Grabit. Professor Black clearly sees her student Tom Grabit grab a library book from the shelf, stick it in his coat pocket, and sneak out the back door of the library. It seems clear that Black knows that Tom stole the book. Suppose the story continues: Tom Grabit,con’t. Tom’s grandmother is hospitalized hundreds of miles away, and is in the grip of many paranoid delusions. At the very moment that Black sees Tom steal the book, Tom’s grandmother is ranting to her nurse, and says,“My grandson Tom has an identical twin brother at Tom’s university who frequently uses the library and is a compulsive shoplifter.” This is false; Tom is an only child. Tom’s grandmother’s delusional rant hundreds of miles away couldn’t possibly affect whether Black knows that Tom stole the book. But now consider the following true proposition: (7) Tom’s grandmother said that Tom has an identical twin brother at Tom’s university who frequently uses the library and is a compulsive shoplifter. If Black learned (7), she would no longer be justified in believing that Tom stole the book. Hence, (7) is a defeater for that belief, and according to nd, Black doesn’t know that Tom stole the book. But this is a very unwelcome result. Defenders of nd have attempted to respond by saying that “misleading” defeaters (like (7)) don’t undermine knowledge. They say that defeaters like (7) are themselves defeated by further defeaters, and that only undefeated defeaters undermine knowledge. We will not be pursuing this strategy"68.100.140.33 (talk) 23:39, 8 April 2015 (UTC)

Grammatical error
Please try to read the second sentence of the second paragraph in the section "Gettier's counterexamples". This sentence contains a long sentence and it appears that there is a grammatical error in it which makes it hard to read. Its hard to read anyway because its so long. Anyway: I think the error is that the second clause does not contain a verb in the right place. The phrase "....counter-example: that is,..." appears to me that for consistency with the earlier part of the clause the verb "is" should appear instead "...counter-example, is ...". However I'm not going to correct it because I don't know what meaning was intended. mildly_odd (talk) 19:35, 29 May 2009 (UTC)

Outsider's comment
I don't understand the need for the depth of commentary in this article. It seems that it really boils down to what one means by "justified". Is this correct, really? If thats the case, why not just say that and cut out 80% of the article? How about this:

JTB = Knowledge when one is "really" justified

JTB <> Knowledge when one "thinks one is justified but isn't really, perhaps because one hasn't thought it through"

As another point, one would only have to express this topic in another language which had different words for the two meanings of "justified" and the problem wouldn't exist at all. Alternatively, maybe this is too simple, maybe it depends upon what one means by "knowledge". Again, I think this could just be spelt out if it is the case. Apologies for being so blunt. I did say I was an outsider. mildly_odd (talk) 19:59, 29 May 2009 (UTC)


 * My impression is that your comments on the Gettier problem more properly pertain to the philosophers' discussion itself than to the Wikipedia article whose task is merely to provide an account of that discussion. In other words, if you could find a philosopher whom you could cite as saying that 80% of philosophers' discussions of the Gettier problem could be eliminated by distinguishing between two senses of "justified", then that view could be cited in the article, though it couldn't be used as justification for cutting 80% out of the article. (I'm not saying that there are no other reasons to edit the article down, instead I have no opinion on that.) The Tetrast (talk) 20:14, 29 May 2009 (UTC).


 * Thanks for your reply, you are partly right - taking your sentences one at a time: (1) you have correctly identified my motivation but I think this page is about JTB, the Talk page is an account of the discussion. There could be another regular page about that subject too, e.g. entitled "long discourses about the Gettier problem", but the page on the Gettier problem itself can be quite short. Sentence (2) unless there is a special definition of philosopher, I need only cite myself in this case. My suggestion that it could all be wrapped up with some better definitions of "Justified" would have to go in another page called "short discorses about the Gettier problem". And then there is your 3rd sentence, which I have no problems with. Regards mildly_odd (talk) 20:56, 23 October 2009 (UTC)

Revert of mention
At first I though that but now I see that. Nevertheless my revert is correct. The Gettier problem is a philosophical problem, and mention of an artist's painting touching on it does NOT belong in an introductory section; mention of a little-known artist does not belong in the article at all. And it did come off like a promotional mention. The Tetrast (talk) 00:23, 16 November 2009 (UTC)
 * I understand - There may be a Gettier problem out there that is not based on a fallacy but it will have to survive much more serious study. Joseane (talk) 11:08, 16 November 2009 (UTC)Triistan (talk) 23:03, 18 November 2010 (UTC)

Technically Not Modern
The first line of this article is at fault for stating that the Gettier problem is "a problem in modern epistemology". The Modern era took place from 1500 to 1960, and the problem was introduced in 1963, therefore it should be recognized as a part of the Postmodern/Contemporary era. —Preceding unsigned comment added by 99.224.105.207 (talk) 20:50, 4 October 2010 (UTC)


 * ✅ —Tom Morris (talk) 11:35, 30 September 2014 (UTC)

Query From a Layman
Wouldn't being justified in one's belief also entail the correct methodology of thought that allows one to come to those conclusions? wouldn't the pan-rational portion of the theory of justification show that a true conclusion confirmed by an outside source, despite being true, would also be un-justified, because one's observation used to achieve the aforementioned justification would have been incorrect, in the case of the farmer's prized cow, the mistake of a black and white piece of paper for the cow would cause the farmer to be un-justified in his belief due to the fact that he lacks the correct observation required for a pan-rational justification. —Preceding unsigned comment added by 148.8.55.45 (talk) 16:34, 18 October 2010 (UTC)

Importance of being Ernest
It is difficult to contend that Wilde anticipated the Gettier problem in his play. I think that reference to it should be dropped from the article.

The position presented by Wilde is arguably more subtle than the Gettier problem. John Worthing's claim to have been christened "Ernest" is "justified" by a convoluted process involving a suggestion by Lady Bracknell that he would have been named after his father and an appeal to the Army Lists, which John only purports to read out. Lady Bracknell then claims to have remembered that his father was indeed called "Ernest". This passage in the play is usually presented as a blatant attempt to fabricate a case supporting the claim that John is really "Ernest", since this will facilitate a good match in the eyes of all concerned. Therefore, in Wilde's view, truth and justification are social conveniences, in which it little matters what anyone knows or believes.

(Revision as of 17:34, 12 September 2011 (edit) (undo) SineBot (talk | contribs) m (Signing comment by 84.xx.xxx.xxx - "- →Importance of being Ernest: new section")

Synonymous expressions
Is this problem basically the same as right for the wrong reason and false basis fallacy? Seems like it to me. Ranze (talk) 00:01, 8 July 2014 (UTC)


 * Sure, except Gettier counterexamples aren't really "fallacies"—they are really intended more as counterexamples to the "traditional" account of knowledge. The poor sucker in the examples aren't being held up as examples of fallacious thinking but as pretty natural mistakes that show traditional epistemology to be inadequate. —Tom Morris (talk) 11:34, 30 September 2014 (UTC)

Copying and pasting someone else's talk topic that seems to have been accidentally put on the main page itself
[Please change this opening sentence; this is not the Gettier problem AT ALL. On the face of it, no epistemologist would classify beliefs based on invalid reasons and faulty premises as knowledge. That's not what's at issue. What is taken for granted in the Gettier examples is that the individual meets all the typical requirements for knowledge, but clearly does not have knowledge. THIS IS A PROBLEM; this is the Gettier Problem. What amendments do we make to our theoretical conditions for knowledge (this is a philosophical question, but who cares that it is--it just has to do with what we want in a theory of knowledge). — Preceding unsigned comment added by 118.92.85.188 (talk) 06:56, 8 April 2016 (UTC)
 * Copied from main page. Seems to be a legitimate concern based on my understanding of Gettier. Have deleted this from the main page.**

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Deleting "Constructing Arbitrary Gettier Problems" section
At some point this section must have been larger, because as is it doesn't fit in very well with the rest of the article. However, I am planning on deleting it unless anyone objects because it gives an inaccurate statement of the main idea of Gettier exampmles, which is not about flawed justification. Rather, it is an argument that JTB is not necessary and sufficient for knowledge. Positing that the justification is flawed would be sufficient to defeat Gettier problem on its face, since no one claims that a true beliefs with a flawed justification is necessary and sufficient for knowledge. Original Position (talk) 17:59, 18 October 2018 (UTC)

Kaarlo Jaakko Juhani Hintikka
Hi, the above person is the only one not presented with also his fist name in the article. Probably OK with Plato or Aristotle, but perhaps not with one of our near contemporaries? T 85.166.162.64 (talk) 09:34, 22 January 2019 (UTC)

Error in this entry
I am new to editing wikipedia, so I don't want to just jump in and fix this, but this entry incorrectly states that Alvin Goldman's 1976 paper attributed the Fake Barn case to Carl Ginet. Although the case does seem to have come from Ginet, Goldman did not cite him in that paper. (If you search for Ginet's name, it doesn't come up at all.) He does mention in later papers that he took the case from Ginet. Burton anatomy (talk) 18:01, 8 August 2020 (UTC)

alternative theory of knowledge
There is a good book by Les Valiant called Probably Approximately Correct (abbreviated PAC). Wikipedia's current article about PAC presents it only as a topic in machine learning, but Valiant wrote about it as a theory of knowledge. I have not researched whether the PAC theory of knowledge has gotten any traction among philosophers as an alternative to the JTB theory or in relation to the Gettier problem. If it has, that probably deserves a mention in this article. I might get around to looking into it sometime, but if someone else wants to do it sooner, that would be great. 2602:24A:DE47:B8E0:1B43:29FD:A863:33CA (talk) 01:12, 13 February 2022 (UTC)

Gettier's Case II Counter Example doesn't make sense
''Smith, it is claimed by the hidden interlocutor, has a justified belief that "Jones owns a Ford". Smith therefore (justifiably) concludes (by the rule of disjunction introduction) that "Jones owns a Ford, or Brown is in Barcelona ", even though Smith has no information whatsoever about the location of Brown. In fact, Jones does not own a Ford, but by sheer coincidence, Brown really is in Barcelona. Again, Smith had a belief that was true and justified, but not knowledge.''

Where did  - or Brown is in Barcelona" -  come from? There is no explanation of why Smith believes this. Has this been edited down until it makes no sense?

I found a better explanation:

Smith possesses good evidence in favor of the proposition that Jones owns a Ford. Smith also has a friend, Brown. Where is Brown to be found at the moment? Smith does not know. Nonetheless, on the basis of his accepting that Jones owns a Ford, he infers — and accepts — each of these three disjunctive propositions:


 * 1) Either Jones owns a Ford, or Brown is in Boston.
 * 2) Either Jones owns a Ford, or Brown is in Barcelona.
 * 3) Either Jones owns a Ford, or Brown is in Brest-Litovsk.

No insight into Brown’s location guides Smith in any of this reasoning. He realizes that he has good evidence for the first disjunct (regarding Jones) in each of those three disjunctions, and he sees this evidence as thereby supporting each disjunction as a whole. Seemingly, he is right about that. (These are inclusive disjunctions, not exclusive. That is, each can, if need be, accommodate the truth of both of its disjuncts. Each is true if even one — let alone both — of its disjuncts is true.) Moreover, in fact one of the three disjunctions is true (albeit in a way that would surprise Smith if he were to be told of how it is true). The second disjunction is true because, as good luck would have it, Brown is in Barcelona — even though, as bad luck would have it, Jones does not own a Ford. Accordingly, Smith’s belief that either Jones owns a Ford or Brown is in Barcelona is true.

Source: https://iep.utm.edu/gettier/

A.A.Mcphee (talk) 01:41, 25 January 2024 (UTC)