stoutfellow: (Murphy)
stoutfellow ([personal profile] stoutfellow) wrote2008-07-22 09:50 am
Entry tags:

Epimenides

"It's a latter-day illustration of the ancient paradox: Cretans always lie, said the Cretan."

Sigh. A Cretan saying that Cretans always lie does not produce a paradox. All that is necessary is to assume that:
  • Cretans sometimes lie and sometimes tell the truth;
  • This particular Cretan, on this particular occasion, is lying.
No paradox. Watch your freaking quantifiers, people!

[identity profile] dan-ad-nauseam.livejournal.com 2008-07-23 04:20 am (UTC)(link)
[livejournal.com profile] stoutfellow obviously dislikes wearing a Godel.

[identity profile] tygerr.livejournal.com 2008-07-23 01:08 pm (UTC)(link)
People keep invoking that "Cretan" business when what they're really trying to say is:

THIS STATEMENT is a lie.

pardox

(Anonymous) 2008-07-25 12:28 am (UTC)(link)
I don't understand your logic. Why would you say that Cretans sometimes lie when the Cretan says Cretans always lie. you know what happens when you assume.
Does that mean that all logic uses assumptions in their logic? assumptions are terrible.

Re: pardox

[identity profile] stoutfellow.livejournal.com 2008-07-25 12:33 am (UTC)(link)
Here's the deal. If someone says "What I am saying right now is false", you get a paradox: assuming that he's telling the truth leads to the conclusion that he's lying, but assuming that he's lying leads to the conclusion that he's telling the truth. Both possibilities lead to contradictions; that's what makes it a paradox. With the Cretan's statement in the post, there is a possibility - the one I described - that doesn't lead to a contradiction, so there's no paradox.

Re: pardox

(Anonymous) 2008-07-27 02:49 pm (UTC)(link)
Understand now. If you specifically say ... always lies then that is not a contradiction. but if you don't mention specifics then it becomes a contradiction. So in the Spock versus the robot episode the robot didn't understand the concept right? Donp