# The Unexpected Hanging Paradox **URL:** \ **Category:** Factual Questions\ **Created:** [September 29, 2009, 4:02pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993 "2009-09-29T16:02:32Z")\ **Posts on this page:** 20\ **Page:** 6
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [October 9, 2009, 10:59am UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/101 "2009-10-09T10:59:20Z")
[QUOTE=jtgain;11643374 bolding mine] Well, the wikipedia article states that academics have been debating the correct solution to this paradox for many years. Please forgive us **mere mortals** who don’t have the **brain capacity** to solve this in two pages of contradictory explanations. [/QUOTE] If **niviac** says something that you happen to disagree with, there are good ways of expressing this and progressing the discussion. Slinging around sarcastic terms that are spectacularly irrelevent to _both_ **niviac** ’s post _and_ the paradox under discussion is unlikely to be the best option, although of course you have that prerogative and there’s no rule against it. This has nothing to do with being mortal, and nothing to do with brain capacity. What **niviac** was conveying was some exasperation (that I think is understandable) with the fact that _some_ particpants in this thread are still proclaiming rather ardently that they can’t see the resolution or don’t understand it, when their posts / problems / objections make it clear that they haven’t bothered to read the information given to them, or at least not in anything but the most cursory way. Sometimes when an explanation isn’t understood, it’s because the explainer isn’t very good at explaining - and indeed back on the first page of this thread I felt it fair to conclude that I personally am rather hopeless at explaining this particular paradox. Mea culpa. But there are other times when the failure is not the fault of the explainer, but the fault of the listener who will not listen or the reader who will not read and will not take a moment to think about the information or the explanation provided. If dry sarcasm about mortality and brain capacity aimed at another Doper _who was trying to help you_ is all you have to offer, well, so be it (although it doesn’t advance the discussion). But I prefer to think better of you. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [October 9, 2009, 3:12pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/102 "2009-10-09T15:12:48Z")
> [@](#): > > That would only be analogous if the game show host guaranteed you that the coin was placed such that you wouldn’t know the coin was under the box before the box was lifted. That’s a guarantee that it’s not under the last box, so with that in mind, wouldn’t you want to put your money on the fourth box after the previous three boxes were lifted? But then that would make the fourth box predictable. Reading this thread and the Wikipedia page, I’m convinced there is no convincing answer to this problem. The similarity is that both situations are based on the logic “I can guess with absolute certainty which possibility will occur when only one possibility exists” - which is correct (and obvious). But then the logic derails when it goes on to “I can now go on to guess with absolute certainty which possibility will occur when multiple possibilities exist.” ---
**Author:** ![PBear42](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@PBear42](https://boards.straightdope.com/u/PBear42)\ **Post date:** [October 10, 2009, 8:43am UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/103 "2009-10-10T08:43:04Z")
**ianzin** , what you are skipping over is that there are several resolutions of the paradox. some of which appeal to some and others of which appeal to others. Broadly speaking, there are logical approaches and epistimelogocal ones. You like an epistimemolgical resolution. In that, the one-day version is as good as the five-day one. I (and others) prefer a logical approach, in which multiple days is the _sine qua non_ of the (apparent) paradox. To say those of us in the logical camp just don’t get it is to assume your view. Surely you can see how that’s not quite kosher. \ ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [October 10, 2009, 1:07pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/104 "2009-10-10T13:07:16Z")
Hi **Pbear42**. Sorry, no offence, but what you have written has nothing whatsoever to do with the point I was making. If you go back and read what I wrote, you will see that this is so. How ironic that this rather confirms what I wrote. I was not commenting on the fact that some people prefer this or that type of explanation. This is completely irrelevant. I was commenting on the fact that _some_ people (and let’s pause for a second to emphasise the word _ **’some’** _) who have participated in this thread have asserted that a given point or explanation does not make sense or fails to resolve the paradox, while their comments indicate that they have not taken the time to read and understand the very points or explanations they are so swift to dismiss. And if it pleases you, I will amend my final clause to say ‘…while _in my opinion_ their comments indicate…’. Just for the record, you are correct about my own views concerning the resolution of the paradox. I believe the easiest way to resolve it is to consider an ‘only Friday’ version, and to consider how we would evaluate any statement analogous to ‘I am stating what is going to happen and I am telling you it will be unexpected’. However, to classify this as an ‘epistemological’ approach or solution is incorrect. It has nothing to do with the word ‘epistemological’. It is a case of logical inconsistency. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 1:31pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/105 "2009-10-10T13:31:24Z")
> [@ianzin](#): > > and to consider how we would evaluate any statement analogous to ‘I am stating what is going to happen and I am telling you it will be unexpected’. However, to classify this as an ‘epistemological’ approach or solution is incorrect. It has nothing to do with the word ‘epistemological’. It is a case of logical inconsistency. I understand–and like–your reading of the paradox. But I have to insist that there’s no inconsistency in the judge’s statements, strictly speaking–as demonstrated by the oft-cited fact that both of the judge’s statements turn out to be true. (They can’t both be true if they are in contradiction). If there’s an inconsistency in the area, it’s not in the statements themselves. See **Indistinguishable** ’s posts above. “X is going to happen, but don’t you believe it!” contains no inconsistency on its face. But there’s something strange–indeed, inconsistency-like, about the utterance nevertheless. That’s because generally when we say “X is going to happen” we signal (but do not say!) that we intend our hearer to believe X is going to happen. The inconsistency is in the pragmatics of utterance, not in the propositional content of the utterance itself. That’s why yours isn’t a “logical” reading. There’s no logical inconsistency. The inconsistency is pragmatic, i.e., has to do with the intended effects and force of the words rather than with their propositional meaning. I think it can be appropriate to call yours an “epistemological” reading because your reading turns on an observation about the usual _intended epistemological force_ of utterances. When I say a sentence “X” generally I intend that others believe “X”. I intend it to have epistemological force. The problem on your reading is that the judge utters statements with intended epistemological forces which end up canceling out. ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [October 10, 2009, 2:48pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/106 "2009-10-10T14:48:40Z")
> [@Frylock](#): > > But I have to insist that there’s no inconsistency in the judge’s statements, strictly speaking–as demonstrated by the oft-cited fact that both of the judge’s statements turn out to be true. (They can’t both be true if they are in contradiction). Back to the ‘tar baby’… I have underlined ‘turn out’ because this is where your assessment of the argument goes awry. My contention is that to assert ‘X shall occur today’ and ‘X is unexpected’ is a logical contradiction. In my reading, the paradox arises because the Judge’s statements involve precisely this logical inconsistency, but the anecdotal wrapping paper (about Friday, Thursday, Wednesday etc.) serves to disguise the fact. The Judge is asserting that something shall happen and also asserting that it will be unexpected. I maintain that I can either know something will happen today, or I can maintain that it is unexpected, but I cannot consistently do both. I can even oscillate between the two views, if there is some room for doubt, but I cannot hold both statements to be true at the same time. You may disagree with my contention and my reading of the paradox. But it is not based on whether anyone, _in retrospect_, assesses two statements to have been true. It is based on the assessment at the time the Judge makes his assertion(s), or at any time before the forecast events have or have not come to pass. It is obviously the case that shifting the time frame makes a difference to one’s assessment of truth values. ‘I do not know what is in this box’ may be true now, but may not be true after I’ve opened it and looked inside. Similarly, the paradox arises because we assess the situation _before_ any of the forecast events have occurred or not occurred. If you invoke a completely different time frame from which to assess things, then you may be doing many useful things but you are not assessing anything that I wrote or contended. I am submitting one argument, and you are attempting to rebut a different one. The curious thing is that my attempting to point this out, or any other attempt, will fail, as **nivlac** has already noted. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 3:10pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/107 "2009-10-10T15:10:52Z")
> [@ianzin](#): > > My contention is that to assert ‘X shall occur today’ and ‘X is unexpected’ is a logical contradiction. Not to ignore the rest of your post, but I think this is key. Your contention here is incorrect. Please understand that to a great degree, I _agree_ with your reading, I just think you are communicating it poorly–indeed, incorrectly–when you say it involves a “contradiction” between those statements. The simple, brute fact is that they are not in contradiction. “X shall occur today” and “X is unexpected” are both _true_ in the scenario you’re discussing. They can’t both be true if they are in contradiction. (Forget about “turn out” to be true–it was not necessary for me to say “turn out.” The fact is, they _are_ true.) Tell me what you think about Moore’s Paradox. ( **Indistinguishable** mentioned this above.) To wit, take the following pair of statements: “It’s raining. I don’t believe it’s raining.”\* Do you think those two statements are in contradiction with each other? -Kris \*Classically, the paradox is given in the form of a single statement: “It’s raining, but I don’t believe it.” ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 4:56pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/108 "2009-10-10T16:56:52Z")
> [@ianzin](#): > > My contention is that to assert ‘X shall occur today’ and ‘X is unexpected’ is a logical contradiction. But that’s not what is stated in the problem. The problem is “You will be hanged on one of 5 days and it will be unexpected.” Are you able to provide anything that shows that a 5 day sequential choice is the same as a 1 day choice? ---
**Author:** ![ianzin](https://avatars.discourse-cdn.com/v4/letter/i/ed655f/32.png) [@ianzin](https://boards.straightdope.com/u/ianzin)\ **Post date:** [October 10, 2009, 4:57pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/109 "2009-10-10T16:57:29Z")
> [@Frylock](#): > > “X shall occur today” and “X is unexpected” are both _true_ in the scenario you’re discussing. They can’t both be true if they are in contradiction. Correct. They cannot. They are in contradiction. A person cannot honestly assert as true both ‘I believe X will occur today’ and ‘X is unexpected’. The former is analogous to ‘I expect X will occur today’. The latter is analogous to ‘I do not expect X will occur today’. Ergo, one cannot hold both to be true at the same time. * * * > [@](#): > > (Forget about “turn out” to be true–it was not necessary for me to say “turn out.” The point about your having introduced ‘turns out’ was not that it was simply ‘unnecessary’. As I explained last time, it fundamentally altered the situation being discussed, and bore no relation to what I had written previously. Now you simply shrug and say, ‘Okay, forget that, it wasn’t necessary’. (My underlining.) So, let’s note the loop we have just had to go on. I submit my understanding of how to resolve the paradox (which of course one may or may not agree with). You mis-state what I wrote and introduce a different time frame which affects the discussion of the logic. I point out why this fundamentally alters the nature of what we’re trying to discuss. You shrug and say, ‘it wasn’t necessary’, which misses the point. It’s not about ‘necessary’ or ‘not necessary’. It’s about mis-representing what I wrote and fundamentally changing the issue under discussion. This all vindicates **nivlac** ’s observation. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 5:02pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/110 "2009-10-10T17:02:08Z")
> [@ianzin](#): > > If you invoke a completely different time frame from which to assess things, then you may be doing many useful things but you are not assessing anything that I wrote or contended. I am submitting one argument, and you are attempting to rebut a different one. The curious thing is that my attempting to point this out, or any other attempt, will fail, as **nivlac** has already noted. On Monday morning there are 2 possibilities, either it’s today or it’s not. It’s not knowable in advance. Your arguments are failing because you are arguing about a different problem, a 1 day choice not a 5 day choice. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 5:18pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/111 "2009-10-10T17:18:18Z")
> [@ianzin](#): > > Correct. They cannot. They are in contradiction. > > A person cannot honestly assert as true both ‘I believe X will occur today’ and ‘X is unexpected’. > > The former is analogous to ‘I expect X will occur today’. The latter is analogous to ‘I do not expect X will occur today’. Ergo, one cannot hold both to be true at the same time. That someone can’t honestly assert P and Q does _not_ mean P and Q are in contradiction. That a sentence is “analogous” to another does _not_ mean the first implies the second. For there to be a contradiction in the logical since, the relationship would need to be “implication,” not “analogy” (whatever exactly you might mean by that). Again, I _understand_ and _am sympathetic_ with what you’re saying. It is just that by couching it in terms of “contradiction” you are obscuring your exposition. Because in fact, there is no contradiction present. I’m trying to _help_ you. Please read my comments above about the pragmatic _force_ of assertion. What you are calling a “contradiction” is not a contradiction, it is a tension between pragmatic forces. This isn’t a niggling point. I am showing you how to express your view correctly, in a way that can be understood. Please tell me whether you think the Moore’s Paradox statements are in contradiction. 1. It’s raining today. 2. I don’t believe it’s raining today. > [@](#): > > The point about your having introduced ‘turns out’ was not that it was simply ‘unnecessary’. I had a difficult time following this and your following comments. For I did not claim that _your_ point was that it was “unnecessary”. Rather, I explained that it was _in fact_ unnecessary. I was telling you that I miscommunicated. What I meant wasn’t that it “turned out” to be true. Rather, what I meant was that, in the scenario, the statements _are_ true. There’s no “shrugging of the shoulders.” I was admitting that I had miscommunicated, and explaining what I really meant. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 5:23pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/112 "2009-10-10T17:23:55Z")
> [@ianzin](#): > > Hi **Pbear42** I was commenting on the fact that _some_ people (and let’s pause for a second to emphasise the word _ **‘some’** _) who have participated in this thread have asserted that a given point or explanation does not make sense or fails to resolve the paradox, while their comments indicate that they have not taken the time to read and understand the very points or explanations they are so swift to dismiss. I just went back and re-read previous posts. You do realize that your own point of view (“judges statement is contradictory”) is in direct contradiction to **nivlac’s** own post regarding the sci am article in which they state the judge’s statement is accurate. So, if you have any kind of logic to back up your assertion that a 5 day choice is the same as a 1 day choice, please, please provide it, I would be truly interested in it. So far I have seen absolutely nothing other than magically waving away a critical part of the problem. **Indistinguishable** , you have also made the claim that 5 days and 1 day are the same. I don’t see it and I am truly curious how the 5 days can be logically converted to 1 day. As I posted previously, on Monday it does not seem possible for the prisoner to predict which day it will be and that is enough for surprise. Do you have any logic you can provide showing how to reduce a 5 day choice to 1 day? ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 5:33pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/113 "2009-10-10T17:33:37Z")
**ianzain** , here’s a follow up to my own previous post. Can you tell me which of the following sentences you think is incorrect (if any)? A. A contradiction is a relationship between two sentences such that it is impossible for both of them to be true (and it is also impossible for both of them to be false). B. In the scenario, the judge’s utterance “You will be hanged” is true. C. In the scenario, the judge’s utterance “You will be surprised” is true. I ask this because it seems to me that all three of the sentences I just gave are correct, and it also seems to me that taken together they imply that the judge’s utterances are not in contradiction with each other. Do they not seem to you to imply this as well? Again, I am pointing all this out by way of showing you that “contradiction” is _not_ the concept you want to use in explaining your view. I am not saying your view is wrong, I am saying you are mischaracterizing it by your misuse of the term “contradiction.” ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 5:51pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/114 "2009-10-10T17:51:27Z")
> [@Frylock](#): > > Tell me what you think about Moore’s Paradox. ( **Indistinguishable** mentioned this above.) To wit, take the following pair of statements: > > “It’s raining. I don’t believe it’s raining.”\* > > Do you think those two statements are in contradiction with each other? > > -Kris > > \*Classically, the paradox is given in the form of a single statement: “It’s raining, but I don’t believe it.” I just went to wiki and read about this. I don’t see any issue. Yes it’s a statement that is in contradiction. However, I can think of no situation in which you could honestly make that statement thinking both parts are true, it’s the same as simply saying 1=2. Seems trivial and uninteresting. What am I missing? The first part of the statement is about a fact, the second part is about what you believe, and the minute you introduce the fact into your brain so that you can communicate the statement then it is part of what you believe and you would no longer make the second part of the statement, unless your brain is simply not functioning properly in which case you might make any kind of unreasonable statement. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 6:16pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/115 "2009-10-10T18:16:58Z")
> [@RaftPeople](#): > > I just went to wiki and read about this. I don’t see any issue. Yes it’s a statement that is in contradiction. > > However, I can think of no situation in which you could honestly make that statement thinking both parts are true, it’s the same as simply saying 1=2. Seems trivial and uninteresting. What am I missing? I can’t speak to what’s interesting about it at this moment, but the reason I brought it up was because I think (similarly to what **indistinguishable** said above) that the judge’s statements are defective in the same way a Moore-ish statement is defective. And standardly, the Moore-ish statement is considered _not_ to be in contradiction. (It’s not–the entire statement can be true. It can be true that it is raining at the same time that it’s true that I don’t believe it’s raining.) Whatever’s wrong with saying “It’s raining and I don’t believe it’s raining,” it’s _not_ that one has contradicted oneself. One hasn’t. There’s something else wrong. I’m bringing it back to **ianzain** ’s attention because I think he’s wrong to say the judge is contradicting himself, but that he might _not_ be wrong to say there’s something defective about the judge’s utterance, something that “feels” kind of like a self-contradiction in the same way that Moore’s sentence “feels” like a contradiction, even though it isn’t. So in other words, here’s a summary of the dialogue as I intended it: **ianzin** : The judge’s statements are contradictory. **frylock** : No they’re not–in fact they’re both true. **ianzin** : But the judge can’t honestly assert both of them. So they’re contradictory. **frylock** : You might be right he can’t honestly assert both of them. But that doesn’t make them contradictory. For example, see Moore (as cited above–and for similar reasons–by **indistinguishable** ). That’s another example of a pair of statements one can’t honestly assert–and yet which are not contradictory. **ianzin** : Oh I get it! So I shouldn’t be saying the statements are contradictory. What I really am getting at is that they have some other kind of defect involving the fact that their rhetorical or pragmatic forces cancel each other out when they are actually uttered. **frylock** That’s what I _thought_ you were getting at, I’m glad to hear you confirm it! **ianzin** Oh frylock, you’re so good at helping other people clarify their thoughts. **frylock** I know right? ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 6:22pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/116 "2009-10-10T18:22:40Z")
Wanted to ETA: [Here](http://plato.stanford.edu/entries/assertion/beliefknowledge.html)’s a discussion that talks about Moore’s sentence in a context that brings out some of its philosophical interest. The article is kind of jumping into the middle of things, though. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 6:36pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/117 "2009-10-10T18:36:20Z")
> [@Frylock](#): > > I can’t speak to what’s interesting about it at this moment, but the reason I brought it up was because I think (similarly to what **indistinguishable** said above) that the judge’s statements are defective in the same way a Moore-ish statement is defective. And standardly, the Moore-ish statement is considered _not_ to be in contradiction. (It’s not–the entire statement can be true. It can be true that it is raining at the same time that it’s true that I don’t believe it’s raining.) Whatever’s wrong with saying “It’s raining and I don’t believe it’s raining,” it’s _not_ that one has contradicted oneself. One hasn’t. There’s something else wrong. > > I’m bringing it back to **ianzain** ’s attention because I think he’s wrong to say the judge is contradicting himself, but that he might _not_ be wrong to say there’s something defective about the judge’s utterance, something that “feels” kind of like a self-contradiction in the same way that Moore’s sentence “feels” like a contradiction, even though it isn’t. > > So in other words, here’s a summary of the dialogue as I intended it: > > **ianzin** : The judge’s statements are contradictory. > **frylock** : No they’re not–in fact they’re both true. > **ianzin** : But the judge can’t honestly assert both of them. So they’re contradictory. > **frylock** : You might be right he can’t honestly assert both of them. But that doesn’t make them contradictory. For example, see Moore (as cited above–and for similar reasons–by **indistinguishable** ). That’s another example of a pair of statements one can’t honestly assert–and yet which are not contradictory. > **ianzin** : Oh I get it! So I shouldn’t be saying the statements are contradictory. What I really am getting at is that they have some other kind of defect involving the fact that their rhetorical or pragmatic forces cancel each other out when they are actually uttered. > **frylock** That’s what I _thought_ you were getting at, I’m glad to hear you confirm it! > **ianzin** Oh frylock, you’re so good at helping other people clarify their thoughts. > **frylock** I know right? I understand you were trying to help **ianzin** clarify his/her point of view. Regarding Moore’s paradox, I will read your other link and see if I can see why it’s not trivial. ---
**Author:** ![Frylock](https://avatars.discourse-cdn.com/v4/letter/f/ce7236/32.png) [@Frylock](https://boards.straightdope.com/u/Frylock)\ **Post date:** [October 10, 2009, 6:39pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/118 "2009-10-10T18:39:14Z")
Sorry to flood the thread, but I want to address the idea that Moore-like sentences are in contradiction again. It is pretty common, in my experience, for people to immediately say the sentences are self-contradictory. You just did it, for example, **Raftpeople** , and that despite having just read a wiki article which says right near the top that the sentence is true–which means it can’t be self-contradictory. I think this is due to an unexamined idea that from “The sky is blue” I can naturally conclude that “I believe the sky is blue”. In other words, people seem to tend to think–at least before they think about it a second time–that “The sky is blue” _implies_ “I believe the sky is blue.” And there is a sense in which _saying_ or _thinking_ or _noticing to oneself_ that the sky is blue does indeed in some way _signal_ that I believe the sky is blue. But importantly, this signaling relation is _not_ implication. “The sky is blue” does _not_ imply “I believe the sky is blue.” This is easy to prove. If X implies Y, then X can not be true while Y is false. But it _can_ be true that the sky is blue while it is at the same time false that I _believe_ the sky is blue. So we can see that “The sky is blue” _does not imply_ that I believe the sky is blue. And this means that the sentence “The sky is blue but I don’t believe it” is not self-contradictory. It might be that by saying “The sky is blue” I _signal_ that I believe the sky is blue, and that by saying “I don’t believe it” I _signal_ that I don’t believe the sky is blue. And the things I’ve signaled are indeed in contradiction. But what I _said_ (as opposed to what I did by saying it, i.e., as opposed to what I signaled) is _not_ contradictory. The reason Moore’s sentence has interested anyone is that it turns out to be illuminating to think about how the sentence goes wrong. It’s not self-contradictory, but there’s something about it that makes it unsayable. Why is that? What I said about “signalling” above is _one_ theory about what makes it unsayable. There are other theories besides. Whichever is correct–and actually I find them all plausible and wonder if some synthesis can be drawn up–by formulating them we learn something about the pragmatics of speech, the epistemology of assertion and testimony, and about the limits (and advantages) involved in treating utterances _only_ for their propositional content. Those are topics which I think should be interesting to a lot of people. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 6:55pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/119 "2009-10-10T18:55:31Z")
> [@Frylock](#): > > Sorry to flood the thread, but I want to address the idea that Moore-like sentences are in contradiction again. > > It is pretty common, in my experience, for people to immediately say the sentences are self-contradictory. You just did it, for example, **Raftpeople** , and that despite having just read a wiki article which says right near the top that the sentence is true–which means it can’t be self-contradictory. > > I think this is due to an unexamined idea that from > > “The sky is blue” > > I can naturally conclude that > > “I believe the sky is blue”. > > In other words, people seem to tend to think–at least before they think about it a second time–that “The sky is blue” _implies_ “I believe the sky is blue.” > > And there is a sense in which _saying_ or _thinking_ or _noticing to oneself_ that the sky is blue does indeed in some way _signal_ that I believe the sky is blue. But importantly, this signaling relation is _not_ implication. “The sky is blue” does _not_ imply “I believe the sky is blue.” This is easy to prove. If X implies Y, then X can not be true while Y is false. But it _can_ be true that the sky is blue while it is at the same time false that I _believe_ the sky is blue. So we can see that “The sky is blue” _does not imply_ that I believe the sky is blue. > > And this means that the sentence “The sky is blue but I don’t believe it” is not self-contradictory. It might be that by saying “The sky is blue” I _signal_ that I believe the sky is blue, and that by saying “I don’t believe it” I _signal_ that I don’t believe the sky is blue. And the things I’ve signaled are indeed in contradiction. But what I _said_ (as opposed to what I did by saying it, i.e., as opposed to what I signaled) is _not_ contradictory. > > The reason Moore’s sentence has interested anyone is that it turns out to be illuminating to think about how the sentence goes wrong. It’s not self-contradictory, but there’s something about it that makes it unsayable. Why is that? What I said about “signalling” above is _one_ theory about what makes it unsayable. There are other theories besides. Whichever is correct–and actually I find them all plausible and wonder if some synthesis can be drawn up–by formulating them we learn something about the pragmatics of speech, the epistemology of assertion and testimony, and about the limits (and advantages) involved in treating utterances _only_ for their propositional content. Those are topics which I think should be interesting to a lot of people. “The sky is blue” as uttered by a person has an implied “believe” in there. It’s the same as saying “I believe the sky is blue”. ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [October 10, 2009, 7:12pm UTC](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993/120 "2009-10-10T19:12:37Z")
Well I read that link and it didn’t help Moore’s paradox sound less trivial, and they kind of mentioned that by stating that “the speaker implies but does not assert” the belief, which seems trivially obvious. Humans make the following statements about facts: 1. What they believe (which is not a fact) 2. Evidence they have that supports the fact regardless of their own personal belief [Previous page](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993.md?page=5) [Next page](https://boards.straightdope.com/t/the-unexpected-hanging-paradox/511993.md?page=7)