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Double Liar Paradox (Jourdain's paradox)


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63 replies to this topic

#61 BrainDrain

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Posted 12 October 2012 - 12:46 AM

In order to truly make this a paradox, you would need to qualify at the beginning that both statements are either true or false.

If both statements are true, it's a paradox because they cannot both be true.

If both statements are false, it's a paradox because they cannot both be false.

There is no such qualifer to this "puzzle"; therefore, it's philosophy.

But it does provoke thought, doesn't it? That's what philosophy does.
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#62 ACuriousMind

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Posted 25 October 2012 - 08:18 AM

Here are the facts:

Front= "THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS FALSE."
Back= "THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS TRUE."



You can start with either side, it does not matter. Let's use "-n" to specify deniability, and let's start with BACK:

Back = Front = -nBack = -nFront = -n-nBack = -n-nFront = -n-n-nBack = -n-n-nFront = -n-n-n-nBack = -n-n-n-nFront = etc. = etc.


It is an infinite loop of deniability. By starting with BACK, first, assumes truth until the loop cycles back to BACK and deniability begins, infinitely. Starting with FRONT initiates the infinite loop immediately, but intuition of using the FRONT, first, should call the question of "when did this start in the first place?" (there was no beginning, it has always been), because we could have started with BACK initially... See how this works?

Added:
This problem has two flows: a reverse flow

Edited by ACuriousMind, 25 October 2012 - 08:25 AM.

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#63 ACuriousMind

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Posted 25 October 2012 - 09:11 AM

The edit rules are very stringent in this forum, and the edit button did not seem to appear after the "10 min rule". Anyway, from my above post, this is supposed to be the finalized edit:

Added:
This problem tends to have a reverse chronological flow, because the mind attempts to unravel the pattern as soon as the illogical loop is recognized, to find any initializing details.
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#64 Martis

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Posted 17 November 2013 - 07:59 AM

Whatever value of truth we assign to any of the statements, we'll be trapped in a contradiction. The resolution of such a thing would be to assert that the two statements aren't correlated. It is assumed that the truth value of one statement affects the other one, but we can state that this assumption is wrong and that they are un correlated, and the problem is solved.
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