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Anime Explains the Epimenides Paradox

1 Post author: Eliezer_Yudkowsky 27 May 2009 09:12PM

The Epimenides Paradox or Liar Paradox is "This sentence is false."  Type hierarchies are supposed to resolve the Epimenides paradox... Using an indefinitely extensible, indescribably infinite, ordinal hierarchy of meta-languages. No meta-language can contain its own truth predicate - no meta-language can talk about the "truth" or "falsity" of its own sentences - and so for every meta-language we need a meta-meta-language.

I didn't create this video and I don't know who did - but it does a pretty good job of depicting how I feel about infinite type hierarchies: namely, pretty much the same way I feel about the original Epimenides Paradox.

Bonus problem: In what language did I write the description of this video?

Comments (26)

Comment author: JGWeissman 01 June 2009 05:23:15AM 3 points [-]

I just Stumbled onto the related Pinocchio Paradox.

Comment author: Alicorn 01 June 2009 12:10:02PM 13 points [-]

That's not a paradox if you distinguish between a lie and a false statement. If Pinnochio does not expect his nose to grow, then he is lying, and his nose will grow; he has lied but in so doing made a coincidentally true statement. If he does expect his nose to grow, then he is telling the truth as far as he is able, and it will not grow, even though he would be mistaken in the statement.

If Pinnochio's nose detected absolute truth, then there really should have been a subplot in the story about people who want to kidnap him and pose him questions to determine the ultimate nature of the universe.

Comment author: [deleted] 10 February 2014 04:32:39PM 1 point [-]

If Pinnochio's nose detected absolute truth, then there really should have been a subplot in the story about people who want to kidnap him and pose him questions to determine the ultimate nature of the universe.

Or just make shitloads of money by asking him about the results of upcoming football matches and betting on them.

Comment author: JGWeissman 01 June 2009 06:35:05PM *  0 points [-]

If Pinocchio's nose detected absolute truth, then there really should have been a subplot in the story about people who want to kidnap him and pose him questions to determine the ultimate nature of the universe.

Ha ha ha. Mad Computer Scientist: "And now, Pinocchio, I would like to you to assert that 'P=NP'."

(I was just primed by reading this.)

Comment author: JGWeissman 27 May 2009 09:55:03PM 2 points [-]

In what language did I write the description of this video?

You seem to have written it in English, a language that offers no protections against paradox inducing self reference.

Comment author: Cyan 28 May 2009 03:42:44AM *  1 point [-]

Eliezer wrote the description of the video in E-prime. Vote me up bitchezzz!!!

(kidding)

Comment author: CannibalSmith 28 May 2009 06:24:52AM 1 point [-]

It's impossible to write "this statement is false" in E-Prime.

Comment author: Eliezer_Yudkowsky 28 May 2009 07:03:19AM 3 points [-]

This statement fails to match reality.

Comment author: Cyan 28 May 2009 02:04:58PM *  3 points [-]

I prefer, "This statement expresses a falsehood."

Comment author: CannibalSmith 28 May 2009 10:51:42AM *  0 points [-]

I did not create this video and I have no idea who did; someone originally named the file truefalsempeg1.mpg.

The Epimenides Paradox or Liar Paradox says "This statement fails to match reality."

Why did I post this video? Well... type hierarchies supposedly resolve the Epimenides paradox. Using an indefinitely extensible, indescribably infinite, ordinal hierarchy of meta-languages. No meta-language can contain its own truth predicate - no meta-language can talk about the "truth" or "falsity" of its own sentences - and so for every meta-language we need a meta-meta-language.

This video does a pretty good job of depicting how I feel about that: pretty much the same way I feel about the original Epimenides Paradox.

Bonus problem: In what language did I write the description of this video?

Comment author: Dan_Moore 01 July 2009 09:06:03PM 1 point [-]

I've long felt that 'This page is intentionally left blank' is Epimenedes-esque. :)

Comment author: Psychohistorian 28 May 2009 12:13:15AM *  1 point [-]

Video may be a wee bit longer than needed to get the point across. And by wee bit, I mean you could cut 7.5 minutes off of it, and it runs for 7:40.

I've always (after a fun paper on this!) thought of this in modal terms. Self-referential statements are not truths about the world; they're truths about ill-defined universes. "This statement is false" doesn't refer to anything; it's its own little world, and consequently truth has no meaning.

Similarly, "This statement is true" really doesn't provide any information. What if it's a false statement? Is there a difference? How can we tell? It's its own self-referential world, and it's unclear what truth even means in that little world, though it's very clear that it does not make the least bit of difference in any world I care about.

Comment author: Eliezer_Yudkowsky 28 May 2009 12:23:33AM 3 points [-]

Video may be a wee bit longer than needed to get the point across.

I believe that's the intended point. Besides, most infinite ordinals are very much larger.

Comment author: Psychohistorian 28 May 2009 12:34:29AM *  3 points [-]

Which is funny, because a ten second clip and a ten-billion-year clip are equally close to approximating infinity.

Comment author: Peter_de_Blanc 28 May 2009 01:53:39AM 1 point [-]

Not in surreal numbers!

Comment author: Peter_de_Blanc 30 May 2009 06:38:47PM 1 point [-]

"This statement is false" doesn't refer to anything; it's its own little world, and consequently truth has no meaning.

What about statements that refer both to themselves and to things in our world, such as "either this sentence is false, or Psychohistorian owes Peter de Blanc $50"?

Comment author: Nick_Tarleton 28 May 2009 12:45:25AM 1 point [-]

This is also how I've always thought about self-referential statements; is there a name for this position? Is it even a position?

Comment author: Psychohistorian 28 May 2009 12:56:29AM 0 points [-]

Modal logic, from what I remember of it, deals with "worlds" of sorts, so it might be possible to express it with modal logic; I don't remember well enough, and I certainly don't recall this being a named position. It does seem like a position, though.

Comment author: MBlume 01 July 2009 08:54:47PM *  0 points [-]

And by wee bit, I mean you could cut 7.5 minutes off of it, and it runs for 7:40.

There's a very pretty bagpipe line that kicks in towards the middle -- wouldn't want to miss that.

Is that the Mingulay Boat Song?

Comment author: dclayh 27 May 2009 09:55:01PM 0 points [-]

Bonus bonus problem: why did you put an abstract break if there's no content following it?

Comment author: Eliezer_Yudkowsky 27 May 2009 11:25:10PM 0 points [-]

There was supposed to be an embedded video there; have added issue for why it doesn't appear.

Comment author: Nick_Tarleton 28 May 2009 02:46:45AM 0 points [-]

There's an <object> tag but no <embed> tag. I assume that's the problem.

Comment author: Eliezer_Yudkowsky 28 May 2009 05:08:04AM 0 points [-]

Yup.

Comment author: knb 28 May 2009 02:40:49AM *  0 points [-]

The video is working fine in Chrome and opera and Safari. Apparently not firefox or IE.

Comment author: hirvinen 28 May 2009 12:08:32AM 0 points [-]

It works in Konqueror and apparently would in Opera if mine didn't have a general problem with youtube. Not in Firefox, though.

Comment author: CannibalSmith 28 May 2009 06:26:09AM 0 points [-]

Someone should make a YTMND of it.