Fuzzy logic

chabibi · #1 06-28-2005, 12:06 PM

linky

My understanding is that with fuzzy logic, statements are no longer broken down in to logical or illogical, but can be partly logical mostly logical etc… It seems to me that this could be used by theists to prove certain contradictions between the bible and conventional science as being only partly illogical. For example if the bible records the earth as being 6000 years old and the earth is in fact 6 billion years old. Assuming the bible records a year as 100 000 revolutions of the earth around the sun then the statement is mostly logical and therefore there is almost no contradiction.

TomCollins · #2 06-28-2005, 02:27 PM

If you assume up means down, left means right, of course nothing is ever false.

chabibi · #3 06-28-2005, 02:42 PM

i think you are missing the point. the idea is that things are not broken down in to true and false but can have many degrees in the middle.

nate1729 · #4 06-28-2005, 02:49 PM

You're off-base here. Fuzzy logic is still precise; some confusion arises from the fact that "fuzzy logic" has become a colloquialism meaning "illogic."

I can assure you that fuzzy logic (in the technical sense used in the article) does not mean "hey, let's fudge some assumptions so that we can jam these statements together."

By the way, I'd recommend learning a little about fuzzy logic. Very interesting stuff.

I actually haven't studied fuzzy logic, but I'd guess this is the explanation for the example used in the article:

Question: Statement P, "This statement is false," has what truth value?

Let t = the truth value of P. Note that t also equals the truth value of ~P, which is 1 - t. So t = 1 - t, so t = .5

nate1729 · #5 06-28-2005, 02:51 PM

See my post below about this having essentially nothing to do with what you think it does; also note that most Bible-following folk would be very unhappy with the idea that the statement "Jesus died for our sins" is 72% true.

David Sklansky · #6 06-28-2005, 07:23 PM

The best thing about fuzzy logic is that it was invented by the father of one of the few authors of a non fallacious poker book.

TomCollins · #7 06-28-2005, 08:38 PM

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i think you are missing the point. the idea is that things are not broken down in to true and false but can have many degrees in the middle.

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I'm not missing your point. Either the earth is 6000 years old or it is not. It can't be both. Illogic is not fuzzy logic.

Zygote · #8 06-28-2005, 09:04 PM

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I'm not missing your point. Either the earth is 6000 years old or it is not. It can't be both. Illogic is not fuzzy logic.

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Perhaps the earth was created old. For example, the bible says Adam was created as a man who would've taken something like 20 years to naturally age. So at Adam's creation, the world was apparently about 20 years old. Maybe god created the earth to appear like it was old, when in fact the earth was only created 6,000 years ago.

My only point is that these issues usually aren't as simple as they apparently seem.

NotReady · #9 06-28-2005, 10:14 PM

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certain contradictions between the bible and conventional science

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I've asked Sklansky this and he hasn't answered yet. What contradictions?

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For example if the bible records the earth as being 6000 years old

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The Bible never says this. Even if it did, Zygote's answer has merit. No one can prove the age of the earth as certain unprovable assumptions are required. I personally believe the earth is much older than 6,000 years, and it could well be the 5 billion I believe science now assigns. But it could be much younger. The Bible doesn't state an age.

snowden719 · #10 06-29-2005, 02:04 AM

This seems rather off to me, as it seems as if we could also say that both P and ~P have a truth value of 1 or 0 and that then the value or P and ~P have equivilant truth value. It also seems to be assuming that the statement "this sentence is false" has a discernable truth value to begin with. Either way, it seems unclear what it means for something to be half truth, can someone give an example of something that would be mostly true that would be a liar's paradox? Although the idea is theoretically interesting, it seems that it's just grasping at straws to try and explain liar's paradoxes.