Gettier Problems & Epistemic Luck Are Distractions And No Problem

This is Mary's husband, and he's tired of this game.
This is Mary’s husband, and he’s tired of this game.

Regular readers will recall I do not think so-called Gettier problems have any force in epistemology. The “problems” only crop up because people make two mistakes: forgetting the difference between ontology and epistemology, i.e. what is and what we know about what is, and forgetting the difference between necessary and local truths. A necessary truth is the law of non-contradiction, which we know is true via a form of induction. A local truth is “George wears a hat” given “All Martians wears hats and George is Martian.” We know this is true via a form of induction, too, helped by deduction.

Best to think of Gettier “problems” through example. This is quoted from Duncan Pritchard’s paper “Virtue epistemology and epistemic luck, revisited” (which I learned of from George Shiber) in which Pritchard quotes Linda Zagzebski (ellipses original):

Suppose that Mary has good eyesight, but it is not perfect. It is good enough to allow her to identify her husband sitting in his usual chair in the living room from a distance of fifteen feet in somewhat dim light […] Of course, her faculties may not be functioning perfectly, but they are functioning well enough that if she goes on to form the belief My husband is sitting in the living room, her belief has enough warrant to constitute knowledge when true and we can assume that it is almost always true […] Suppose Mary simply misidentifies the chair sitter, who is, we’ll suppose, her husband’s brother, who looks very much like him […] We can now easily amend the case as a Gettier example. Mary’s husband could be sitting on the other side of the room, unseen by her. (Zagzebski 1996, 285-7, emphasis in the original)

We’re meant to be suspicious that Mary has true knowledge because she flubbed and misidentified the chair sitter, yet the proposition of interest “My husband is sitting in the living room” is still true (it is said). But you can see the mix-ups I mentioned. Mary’s truth is a local one, conditional on the premise “I see a man I identify as my husband sitting in his usual chair”. To us, from our perspective, we see Mary’s premise is wrong. But to us, from our perspective, the proposition “Mary’s husband is sitting in the living room” is also locally true conditional on another premise (un-assumed to Mary but assumed by us) “Mary’s husband is sitting in that chair over there.”

The proposition “My/Mary’s husband is sitting in the living room” is not a necessary truth, which is to say, it is contingent. And all our knowledge of continent propositions is in some way based on local truths, which means Gettier “problems” are no problem at all. Unless we’re meant to talk of knowledge only with respect to necessary truths, which is, I suppose, a definition of sorts. But then we’re in a world of hurt because in order to speak of what is, we first have to use our senses, which are contingent.

We have to also keep in mind our goal: is it ontological or epistemological? If it is only to say or guess or bet or decide whether or not the proposition of interest is true, then in the above scenario Mary wins and so do we. But if it is to remove as much as possible of the contingency of the premises for the proposition, then Mary loses and we win. Why? Because it is a local falsity that “Mary’s husband is sitting in his usual chair” given “Mary’s husband is sitting in that chair over there”. We haven’t removed all contingency because it is not necessarily true that Mary’s husband should be anywhere.

Enter epistemic luck. You’re filling out this quiz: “Progressivism is (A) Harmful, (B) Stupid, (C) Degrading, or (D) All of the above.” Suppose you went to a standard government-sponsored school, complete will all the latest educational theory, then you will not know the answer to the question, so you guess. Eenie, meanie, minee, moe…you pick D.

Now D is the right answer. And we, from our perspective, know D is the right answer conditional on the things progressives do, along with assorted other facts. But, lo, you had no idea D was correct. You were just lucky; you have hit upon knowledge via no effort. So once again, it is hinted, epistemology is in trouble.

Again, the goal of the analysis is mixed up. If the goal is to get the right answer, then you win. You don’t always win in tests that you haven’t studied for, but this time you do win. But you don’t, before the answer is revealed, know D is right. You have made a decision, and decisions aren’t probability (or knowledge). You only have the premise “There are four answers, one of which has to be true.” From that you reason, “D is true” has probability 1/4. (Or maybe you add a premise about tricky “All of the above” questions, but the point is the same.)

If the goal of the analysis was to examine your premises in relation to the decision you made, then we realize you did not have knowledge of D. To have knowledge “D is the right answer” your premises would have had to have been “The things progressives do, along with assorted other facts”. You didn’t know that, so you lose. This mix-up, incidentally, is why multiple-choice questions are an unreliable or at least a weak form of knowledge assessment. But they sure are easy to grade.

This example doesn’t quite capture all what is meant by epistemic luck. Here’s another example from Pritchard (also modified from another):

[C]onsider an agent who is forming a belief about what the temperature of the room is by looking at a malfunctioning thermometer, the reading on which is randomly fluctuating within a certain temperature band. Suppose further, however, that this way of forming beliefs about the temperature of the room is entirely reliable because, as it happens, there is someone hidden in the room—a ‘helper’—who controls the temperature of the room and who ensures that every time our protagonist goes to check the thermometer, the reading it gives is correct

Philosophers like say “agent” when they mean “man”. Anyway, the “agent”‘s “beliefs do not amount to knowledge” because “they do not get to the truth via their cognitive characters, but rather due to luck”. The same goal mix-up happens here. If we checking if the man had the right temperature, he wins; else if we’re checking if he had the right premises, he loses. Simple as that.

We still need to discuss the awful terminology which is “possible worlds.”


  1. Summary: Guessing and “accidently” correct beliefs are not knowledge. Right?

  2. Gary

    I’ll chalk up the several typos to what your enemies put in your eggnog. 😉

    Can the multiple choice format be reconstructed to be a stronger form of knowledge assessment?

  3. Anon

    This is not meant to be flip, but suppose Mary’s husband’s brother is exhibiting other traits that he may share with his brother that are not necessary detected visually? Perhaps a penchant for belching B-flats, or smoking a particular kind to pipe tobacco?

    I have confused my husband’s father for my husband on the telephone, and probably said things I shouldn’t have. This is in the days before of caller ID.

  4. This essay is exactly why I have never formally studied philosophy since college. What a bunch of malarkey (not Briggs — the people Briggs is talking about) dressed up as profound thinking. I cannot cope with people who make propositions about what Mary sees with her semi-bad eyesight and, by doing so, think they have alerted the world to the depressing truth that anything is possible so you might as well give it up and listen to emo music in the dark for the rest of your life, because what’s the point? “People are sometimes wrong but that does not negate logic” does not seem to me to be a proposition one needs an advanced degree or special knowledge to affirm. I’ve read “The Name of the Rose,” of course it is in theory possible to reach correct conclusions based entirely on false propositions and mistakes. Ain’t life funny that way? But every action we take and every thought we think for every moment of the day depends on it being true that we do get things right most of the time and we do have a grasp of reality. Mary pretty much always knows whether or not her husband is in the room, IN THAT CHAIR, and if she didn’t we would quickly stop paying attention to what Mary said. And I have stopped paying attention to the stories about Mary and the people who make them. Question for Zagsgebski: If Mary’s husband Bruce IS in the room, but he says he’s actually a woman, does she actually know her husband when she sees him? Or does she just know his name? And if he says his name is now Caitlyn, DOES SHE KNOW ANYTHING AT ALL?

  5. I’ll borrow a comment from a college classmate when he was confronted with tidbits like the above: “interesting but not useful”.

  6. Milton Hathaway

    Typically the stuff written in His Majesty’s blog concerning the nature of truth and knowledge goes way over my head. As an engineer, truth and knowledge are applied to a problem, and the measure of the truth and knowledge is in the result. I.e., does the bridge fall down? Engineers tend to look down on others who claim to traffic in truth and knowledge but produce nothing measurable.

    But experience has exposed me to a number of what might be called ‘Gettier Solutions’, where the design works, but not for the reasons the designer believes. Typically this happens when a designer lacks sufficient knowledge in a technical area to adequately understand the underlying nature of the problem to be solved, and takes a guess, then tests the guess. Through trial and error, the designer can come up with a workable design without a proper understanding of how it works.

    All’s well that ends well, right? Well, not necessarily; if a designer continues to apply misunderstood principles, when failure finally comes it can be catastrophic. This happens often enough that it has it’s own descriptor, “designed-in quality versus tested-in quality”.

    The caveat here is that nobody truly understands anything, if you dig deep enough. Years ago, I marveled at the marketing guy who asked me how something worked, then cut me off after I had laid the barest foundation of an explanation. But then I realized that he had what he needed to do his job, and the exercise would have been much the same if I had asked a research scientist to explain some principle to me.

  7. Joe Born

    “Typically the stuff written in His Majesty’s blog concerning the nature of truth and knowledge goes way over my head. ”

    Or perhaps it’s the nature of PhDs to see profundity in utterances no more startling than that a squirrel’s occasionally finding nuts doesn’t alone disprove its blindness.

  8. Joy

    May it Be, perhaps? that Mary knew all along?
    People are often right for the wrong reasons.

  9. Briggs


    These kinds of things are not uncommon. 20th century philosophers in particular had a penchant for skepticism, often questioning the possibility of true knowledge. Many were convinced it was true—they knew it was true!—that it was not possible to know anything with certainty. Hence “problems” like Gettier’s.

    I blame a lot of it on Hume, who did manage to confuse the world with his arguments against induction, which are still persuasive to many today.

  10. Paul

    I used to think that Gettier problems were just a nuisance but after I read Zagzebski’s excellent book I completely changed my mind. The issues raised are real ones despite the fact that most epistemologists present them poorly. She’s right in claiming that JTB accounts are in a serious bind and that ad hoc amendments to the ‘justification’ condition are inadequate. Sure, you can solve the problem by dropping the J element or the Truth element altogether but that’s just as bad.

    Her result is not scepticism but rather the application of virtue theory to the analysis of knowledge. So I’m a bit surprised in the way you parse the issue.

    The relevant section is p283-299 (Virtues of the Mind).

  11. “I blame it all on Hume” would make a great t-shirt.

  12. Briggs


    Well the J part to Mary is off from the perspective of the other people, which I agree with. But her local and not necessary argument is on the money. I’m not disputing Mary doesn’t have complete or universal knowledge according to JTB. I’m saying her local argument is itself a JTB.

    Her local argument is conditional on her tacit, and false and contingent, premise her eyes are working. My point is that since we’re routinely dealing with the contingent, more of our arguments than we think of are local. So I emphasize the goal (right prediction or right premises). Her premise that she sees her husband we say is false, yes? And we know that it is false conditional on knowing where her husband really is. So we’re claiming knowledge based on JTB. We can’t analyze any argument without accepting we can have knowledge.

  13. Gary

    I blame a lot of it on Hume, who did manage to confuse the world with his arguments against induction, which are still persuasive to many today.

    Oh, the Hume-inanity.

  14. JH

    Joy, may I recommend this post and its comments (a great example of academic discussions)?

  15. JH

    A necessary truth is the law of non-contradiction, which we know is true via a form of induction.

    “Squares have four sides” is a necessary truth. So how do YOU know it is true via a from of induction? What form of induction? Definitely not mathematical induction.

    The proposition “My/Mary’s husband is sitting in the living room” is not a necessary truth, which is to say, it is contingent.

    The proposition “Square are round” is not a necessary truth, however, is it contingent? No.

    If “My/Mary’s husband is sitting in the living room” is a contingent truth, then it means that “My/Mary’s husband is NOT sitting in the living room” could have been true.

  16. Briggs


    Little problem with English, there. It’s the principle of non-contradiction which we know by induction, not that “squares have four sides”, which is a definition (almost) and not a truth. Which type of induction works for non-contradiction? I promised later I’d give more details. But for now it’s what Aristotle, Groarke, and others call “induction-intellection”. Senses provide information of the here-and-now (or there-and-then), but induction-intellection tells us what is always true everywhere and everywhen. We move with certainty from the particular to the general, from the finite to the infinite. Without this kind of induction, no argument can ever get anywhere, no argument can ever even start; without it language would not be possible. See Groarke’s book or Philosophical Analysis, Volume 55: Shifting the Paradigm: Alternative Perspectives on Induction edited by by Biondi and Groarke for more details.

    It is true that “squares are round” is not contingent; it is false given the definition of squares given above (another example of the difference between necessary and local truths). And it is also true “Mary’s husband sits here” is contingent.

    Pigliucci is good to read on Gettier non-problems, because he is an excellent example of how thinking goes wrong. He also doesn’t see that he needs to assume JTB-as-knowledge to even argue that JTB-as-knowledge is wrong or incomplete.

  17. JH

    I did read it incorrectly. So, how do you know the PNC or the necessary truth of the PNC by induction? I suspect that you will need an example of necessary truth to answer this question. What does it mean to say that you know something?

    Well, to know and by induction, so it’s safe to say that “denying it is self -contradictory” won’t be your answer. Please give me the exact page numbers if the answer can be found in the bookPhilosophical Analysis, Volume 55. I rather read it myself.

    “Squares have four sides” is not a necessary truth? Really?

    I am not a scholar of Aristotle or Hume. One of the authors honestly admits that he is a scholar of Aristotle but not of Hume and is puzzled by Hume’s views, so I will take his word for it –
    “Given such reactions from an Aristotelean studying Humean, I expect similar reactions from Humeans… studying Aristotle.”

    Pigliucci is good to read on Gettier non-problems, because he is an excellent example of how thinking goes wrong.

    *sigh*, exactly the response I expected. Is it possible for you to respond differently with your free will?

    He also doesn’t see that he needs to assume JTB-as-knowledge to even argue that JTB-as-knowledge is wrong or incomplete.

    He doesn’t? Are there other possibilities (see the title and footnotes of his post and the comments)? Could you come up more charitable assumptions, I mean?

  18. Briggs


    “What does it mean to say that you know something?” By JTB, which is the point of this article.

    “Please give me the exact page numbers if the answer can be found in the book Philosophical Analysis, Volume 55. I rather read it myself.” The whole book is worth reading and is highly recommend, as is Groarke’s stand alone book, which I’m guessing you haven’t read. But Groarke’s article in the book you ask about is page 455 to 514. That article also answers the “how” question you had.

    “‘Squares have four sides’ is not a necessary truth? Really?” Really. It is a definition, and an incomplete one at that. Consult any text on geometry to learn why.

    “I am not a scholar of Aristotle or Hume. One of the authors honestly admits that he is a scholar of Aristotle but not of Hume and is puzzled by Hume’s views, so I will take his word for it…” Taking somebody’s word for it without bothering to put the effort into studying yourself can lead to difficulties. And has.

    “*sigh*, exactly the response I expected.” It should have been, because Pigliuccis is wrong.

    “Could you come up more charitable assumptions, I mean?” My response is not an assumption, but a claim, and one I demonstrated. It would uncharitable to call a mistake a truth.

  19. Joy

    JH, does that symbol mean JH? It’s a new one.
    I remember when I thought your name was John spelt Jhon! (with help from my mischievous screen reader) I just thought you’d played with the letters.
    So you were John. All Johns I know are male.
    Once I realised you were JH I still thought you were male! The secondary assumption stuck along with the first mistake.
    It all made sense when I realised that mistake. A LONG time after i’d worked out that you were sweet, sensitive and not John-like and only when you told me, actually.

    When I first read this post I thought it was clear enough. The more I thought about it the more confused I became!
    “Shall I keep reading to understand what the confusion’s about?” Now I’m thinking I’ve missed something really important.
    In other words my impression is that I don’t think there’s a problem, I have to second think this to make it a problem. It’s about perspective, without which we’re all at sea without a compass.
    At least I’m clearer about induction. This is like the grammar of thinking.
    That’s about it and don’t fall out you two!

  20. A friend of mine was captaining a vessel out of a port where a 90 deg left turn had to be managed. The vessel he was captaining was some 300 ft in length and making the turn required a moderate amount of attention. His Conn officer was directing the evolution out of the port. The Captain was supervising because he was nervous. This wasn’t a simple straight out to sea process. He was watching the markers on the edge of the canal that was the egress route. He stumbled a little here. He realized too late that the turn should already have commenced and he shouted.


    His Conn officer complied “Commence Starboard Turn, 30 degrees rudder!”

    The boat began to turn. The Captain slapped his head at his own stupidity and passed the followup order of “All Back Emergency Stop”… Tugs were called to extract them from the problem.

    We have nomenclature and procedure to help us resolve such problems. The Captain accepted his fault. He knew exactly how he screwed up. His Conn officer knew exactly how he had screwed up.

    The communication had failed.

    Except .. Listening to the story I wondered. How had the communication not failed. Although “Right” had been improperly translated to “Starboard”, it was translated properly. How do you define starboard to someone? That’s easy.. It is the right hand of the ship as you are facing the bow. How do you define the right hand? … For many people out there, you make an L shape with your thumb and index finger. The one that is correctly oriented is LEFT…

    The communication that happened between Captain and Conn never happened again. The Captain learned from his mistake. Not only did he refrain from using RIGHT in commands, he also discussed evolutions and markers more thoroughly before executing them.

    How do you pass this lesson on to the next generation without them experiencing some variant of it? There are still people out there who can listen to the mistakes of others and learn a little from them. Only sometimes does the real lesson penetrate though. Too many times I have “learned” lessons from stories like this only to have a variant actually happen to me which taught me the real point. I can’t express the real point. I just know that even though the communication between Captain and Conn was an abject failure, it was also the reason that most of us can get from point A to point B without dying.

  21. JH


    Do 100 jumping jacks, stop and stand still with your eyes closed, and listen to your heart beats. Empty you mind. When you are done, go back to your computer or whatever device you are using, check out the definition of necessary truth.

    Thank you for the page numbers. So, Groarke puts forth an alternative explanation of induction. You agree with his explanation and believe that his explanation allows you to know principle (just to go along with the word used in the entire book) of non-contradiction.

    No more comments as I set out to find out an answer about something else, and I think I have found the answer.

  22. JH


    The character means Zen. It is not my name. My Chinese name means “golden child,” 🙂 and my younger brother name means “king.” So as his sister, he introduces me to his friends as Princess JH. And I am not kidding.


    I like your story, which reminds me of a Zen koan.

  23. JH

    Briggs, the necessary truth link didn’t work. Please check out any book on simple formal logic. Or just google it.

  24. From a comment section on a blog I read–
    On saying “Google it”:
    that’s so hilarious, the “Google It” response we get from people who are too clueless to realize that a debater must bring facts and evidence to the discussion rather than rely on a nebulous possibility that somebody else had posted it on the net for Google to catalogue

    Says it all

  25. Sheri, I take exception to your criticism of “Google it”. Rather than spending my time paraphrasing other comments (some from Stanford Encyclopedia of Philosophy), I urge those to read what other people have to say. I’ve learned more from the internet (and Googling) than I did in many of my undergraduate and graduate classes.
    I don’t evaluate my own expertise in framing arguments so high that others can’t do a better job.

  26. Your exception is noted but rejected. It’s fine to briefly paraphrase what someone said and then provide a link to someone who said it better.

    I will note that my insistance on this is related to my college writing professor who docked a paper I wrote for killing off my characters. I pointed out Shakespeare did this. She said Shakespeare was wrong too. I stopped trying to use “superior” examples thereafter and just did as requested.

  27. JH


    On saying “Google it”: …

    I am not sure what contribution your comment has towards the discussion, but the intent is clear.

    Go to and use key words “necessary truth simple (or basic) formal logic.” Or visit I promise it’d require less time than it took you to write the above quoted comment.

    (I don’t know why the necessary-truth link doesn’t work. I resubmitted it and was told that it appeared to be spam. It’s possible that Briggs, the site administrator, still can access the link. It is a link, in which somehow the copy-and-paste functionality is prohibited. Otherwise, I would’ve copy-and-pasted the entire page.)

  28. JH

    Sherri, oh… I know, Briggs should really have paraphrased the definition of square (though the definition is simpler than the one of necessary truth to some people). Who has a copy of his yet-to-be-published book?! Plus, how clueless he is?! If it’s written in a book, it must be right.

  29. JH: My comment on Googling it is as relevant as your comment “Do 100 jumping jacks, stop and stand still with your eyes closed, and listen to your heart beats. Empty you mind.”

    The definition of a square is equal sides, four right angles. Was that difficult?

    Philosophy pages says:
    Distinction between kinds of truth. Necessary truth is a feature of any statement that it would be contradictory to deny. (Contradictions themselves are necessarily false.) Contingent truths (or falsehoods) happen to be true (or false), but might have been otherwise. Thus, for example:
    “Squares have four sides.” is necessary.
    “Stop signs are hexagonal.” is contingent.
    “Pentagons are round.” is contradictory.

    So squares having four sides is a necessary truth but an incomplete definition.

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