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Flat-Earther's, I challenge YOU to disprove this logic!

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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« on: February 17, 2006, 01:27:18 PM »
"IF EVERYHTING IN THIS SENTENCE IS TRUE, THE EARTH IS ROUND".

I have just proved the Earth is round.

Clear Explanation:

o We start with the following sub-argument.

o Premise, just for this sub-argument: "If A is true, the Earth is round". Call this premise A.

o Suppose A is true. Then:

+ If A is true, the Earth is round

+ So the Earth is round (still supposing A).

o That's the end of the sub-argument.


# We've shown that if A is true then the Earth is round

# But that's what A says.

# So A is true.

# But if A is true, the Earth is round

# So the Earth is round!

Mathematical Set Notation:

Let us denote by Y the proposition to prove, in this case "the Earth is round". Then, let X denote the statement in the box, which asserts that Y follows from the truth of itself. Mathematically, this can be written as X = (X → Y), and we see that X is defined in terms of itself. The proof proceeds:

1. X → X

    identity

2. X → (X → Y)

    substitute right side of 1, since X = X → Y

3. X → Y

    from 2 by contraction

4. X

    substitute 3, since X = X → Y

5. Y

    from 4 and 3 by modus ponens


I look forwards to your replies.
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Pesto

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #1 on: February 17, 2006, 01:42:17 PM »
Stop it.
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nd that, my liege, is how we know the Earth to be banana shaped.
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #2 on: February 17, 2006, 01:46:16 PM »
I'm merely waiting to see if anyone can attempt to disprove it. This logic is better than the majority of FE logic, after all.
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flyingleaf

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #3 on: February 17, 2006, 02:53:20 PM »
I want to say something about corollaries and how an anti-corollary to your statement cannot be also true but is, but somehow can't remember the correct term for it.
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logic!

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #4 on: February 17, 2006, 11:30:57 PM »
They won't get it.

From what knowledge I have of logic, you're committing multiple fallacies. First of all, you're begging the question. Second of all, it seems to me that you have too many conditional statements.
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #5 on: February 18, 2006, 10:25:51 AM »
Obviously there is a flaw there, it's just hard to spot.
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logic!

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #6 on: February 19, 2006, 12:00:51 PM »
Quote from: "cheesejoff"
Obviously there is a flaw there, it's just hard to spot.

Did I get it?
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #7 on: February 19, 2006, 12:12:23 PM »
*edit*
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Prof. Deathninja McSex

Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #8 on: February 19, 2006, 07:06:20 PM »
No silly, your wrong because you spelt "everything" wrong. Your argument now lies in ruins as does your childish notions of a round Earth.
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ZOOBTRON

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #9 on: February 20, 2006, 02:59:27 AM »
Hmmmm. I think your pathetic attempt at logic has only been made possible by a slight retardation of your brain during your formative stages. The evidence I sight is the fact you took two separate and longwinded attempts to simply state: If argument A (earth is round ) = true then earth is round. This is easily proof by logical progression that cheesejoff = special olympics candidate. Anyway...a reply that you were awaiting:

o Premise, just for this sub-argument: "If A is true, then cheesejoff has the logic understanding of a typical block of semi-matured". Call this premise A.

o Suppose A is true. Then:

+ If A is true, then Cheesejoff is a cheddar component

+ So the Cheddar is not capable of cognitive decision (still supposing A).

o That's the end of the sub-argument.


# We've shown that if A is true then the cheddar is daft

# But that's what A says.

# So A is true.

# But if A is true, the Earth is flat due to the round earth deception being defended by the lifeless forms of cheese products ( I sight evidence being the opening argument of this thread ).

# So the Earth is flat!


I look forward to having a burger with cheese. BURNT.
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #10 on: February 20, 2006, 08:16:55 AM »
Zooby, was that an attempt to make yourself feel "special" by using incredibly witty, scathingly insulting and totally original complex insults such as calling me "slightly retarded"? Or is that what passes for an argument on a flat Earth?

Quote from: "ZOOBTRON"
Anyway...a reply that you were awaiting:


Erm, no, I asked you to disprove my logic. Not flame me.

So, if I'm a retard with the "logical understanding of a typical block of semi-matured", and you can't even disprove me, what does that say about you?
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Sharky

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #11 on: February 20, 2006, 08:29:22 AM »
IF EVERYHTING IN THIS SENTENCE IS TRUE, THE EARTH IS FLAT".

I have just proved the Earth is flat.

Clear Explanation:

o We start with the following sub-argument.

o Premise, just for this sub-argument: "If B is true, the Earth is flat". Call this premise B.

o Suppose B is true. Then:

+ If B is true, the Earth is flat

+ So the Earth is flat (still supposing B).

o That's the end of the sub-argument.


# We've shown that if B is true then the Earth is flat

# But that's what B says.

# So B is true.

# But if B is true, the Earth is flat

# So the Earth is flat!

that was stupid
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6strings

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #12 on: February 20, 2006, 06:54:17 PM »
This is possibly the most disturbingly stupid argument I've seen in a while, not because of the initial premise that started the argument, as Flat earther logic does tend to be a similar sort of circular reasoning, only not quite as evident as this one, but because you're all participating in it.

What the hell?  You know it's circular logic (If B is true, then A is true; if A is true, then B is true) and flawed by its very premise, why are you partaking?

The only good thing about this conversation was Zoobtron's mockery of your logic.  Congrats Zoobtron, you're my hero.
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #13 on: February 21, 2006, 01:32:58 AM »
Quote from: "6strings"

What the hell?  You know it's circular logic (If B is true, then A is true; if A is true, then B is true) and flawed by its very premise, why are you partaking?


Read the mathemtical set notation, "retard".
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #14 on: February 21, 2006, 11:13:32 AM »
Quote from: "ZOOBTRON"
If argument A (earth is round ) = true then earth is round.


You fail to understand. It's more like: If A states: "If argument A = true, and if A = (If A is true, Earth is round) then Earth is round" then A is true.

Once again, read the mathematical set notation.
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johnsmith

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #15 on: February 22, 2006, 02:28:30 PM »
This is so simple to proof for a flaw. Your logic consists of an IF A THEN B type thing, so you have A->B.

Then thing is, you never do setup the '->' part.

It's like saying

If 5+3 = 8, then 11+1=72

There's no reason the then should be true or not, based on whether the if is true or not.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #16 on: February 22, 2006, 04:04:05 PM »
Quote from: "johnsmith"
It's like saying

If 5+3 = 8, then 11+1=72


No, it's not like saying this, because this implication is simply false.  The difficulty with the original "implication" is that it is self-referential in a way which cannot be represented by the classical logics.  If you try

  A = A -> B

then you're saying

  (A -> (A -> B)) and ((A -> B) -> A)

This is not a tautology, since asserting A and ~B falsifies it.  In fact, its verity is equivalent to that of "A and B".

Proof: substituting (~x or y) for (x -> y), we get

   (~A or (~A or B)) and (~(~A or B) or A)
= (~A or B) and ((A and ~B) or A)   by DeMorgan
= (~A or B) and ((A or A) and (~B or A))  by distribution
= (~A or B) and (A and (~B or A))
= (~A or B) and A  by A -> x or X
= (~A and A) or (B and A)  by distribution
= B and A  cuz ~A and A is a false.

If you try nth-order logic, you're totally screwed; you simply can't represent the statement anymore.

-Erasmus
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Peter_Godly

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #17 on: February 24, 2006, 03:38:19 PM »
Logic does not concern the veracity of an argument, only its validity.
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #18 on: February 25, 2006, 01:35:43 AM »
I suppose that's true, after all

2+2=4
2+3+4

The Moon is made of Cheese is a valid argument.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #19 on: February 25, 2006, 09:17:53 AM »
Quote from: "cheesejoff"
I suppose that's true, after all

2+2=4
2+3+4

The Moon is made of Cheese is a valid argument.


Good point... all propositions logically follow from a contradiction?
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #20 on: February 25, 2006, 02:46:11 PM »
Quote from: "Erasmus"
Good point... all propositions logically follow from a contradiction?


Well sort of...an argument is invalid if the premises are true and the conclusion is false.

Trees exist
Paper comes from trees

Therefore paper does not exist. This argument is invalid as the premises are true but the conclusion is not.

In the case of a contradiction, since the premises cannot be true, there is no way it can be invalid.

It still doesn't mean the conclusion actually IS true, but the argument is still valid.
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Peter_Godly

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #21 on: February 26, 2006, 10:46:16 AM »
Quote from: "cheesejoff"
Quote from: "Erasmus"
Good point... all propositions logically follow from a contradiction?


Well sort of...an argument is invalid if the premises are true and the conclusion is false.

Trees exist
Paper comes from trees

Therefore paper does not exist. This argument is invalid as the premises are true but the conclusion is not.

In the case of a contradiction, since the premises cannot be true, there is no way it can be invalid.

It still doesn't mean the conclusion actually IS true, but the argument is still valid.

The validity of an argument has nothing to do with the veracity of the premises. Logic only evaluates the form of an argument. This makes it a useful tool, but logic is only a small, specific part of reason.

For the argument presented to be valid in accordance with Propositional Logic, you'd have to structure it this way:
If trees exist, and paper comes from trees, then paper does not exist  (T & C)--> -P             Assumption
Trees exist.                                      T      Assumption
Paper comes from trees.                   C     Assumption
Therefore, paper does not exist.         -P     Modus Ponens

The above is a valid argument.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #22 on: February 26, 2006, 11:05:25 AM »
Quote from: "Peter_Godly"
The above is a valid argument.


What?

What do you think "valid" means?
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Peter_Godly

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #23 on: February 26, 2006, 01:00:02 PM »
Validity means it adheres to logic.
http://en.wikipedia.org/wiki/Validity

Please note that validity does not mean that the premises are true, only that if they are true, then the conclusion must also be true.

You will notice that examples of logic often only involve letters as representations of premises.

Like
A --> B therefore C

The premises they actually represent are incidental. The utility of logic becomes apparent when the conclusion is clearly absurd. If the argument is valid, then you can be sure that the problem is with one or more of the premises. Then you ask them to logically support a premise you have an issue with. Then they form a valid argument to support that, and flaws may or may not (if they're right after all) pop up in those premises.

Or, if the premises look like they're true, and the argument is valid, but the conclusion is absurd, that is also useful. This is a sign that perhaps a premise you thought was true actually isn't, or that the conclusion only seems absurd, but is actually some kind of revelation.

Logic is only a supplement to judgment, not the entirety of it.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #24 on: February 26, 2006, 11:11:47 PM »
Quote from: "Peter_Godly"
Please note that validity does not mean that the premises are true, only that if they are true, then the conclusion must also be true.


Yeah so how does "(T & C) --> -P" constitute a valid argument?  Suppose it happens that T & C, but also P; a true antecedent with a false consequent refutes an implication.

I assure you that I need no lectures on logic.  It just seems to me that your assignment of labels like "valid" to some arguments and not to others follows neither the rules of logic that I'm familiar with, nor those that *you* are familiar with.  What gives?

-Erasmus
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #25 on: February 27, 2006, 03:42:39 AM »
Quote from: "Peter_Godly"
If trees exist, and paper comes from trees, then paper does not exist  (T & C)--> -P             Assumption
Trees exist.                                      T      Assumption
Paper comes from trees.                   C     Assumption
Therefore, paper does not exist.         -P     Modus Ponens

The above is a valid argument.


Quote from: "Peter_Godly"
Please note that validity does not mean that the premises are true, only that if they are true, then the conclusion must also be true.


Hold on, in the paper and trees example, if the premises were true, the conclusion woud not be true. There is no way you can know what a non-existant substance is made from. Therefore, according to your rules, it is not a valid argument.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #26 on: February 27, 2006, 09:36:36 AM »
Quote from: "cheesejoff"
Hold on, in the paper and trees example, if the premises were true, the conclusion woud not be true. There is no way you can know what a non-existant substance is made from. Therefore, according to your rules, it is not a valid argument.


Okay, so, good, I'm not out of my mind.  There seems to be a serious disconnection between syntax and semantics going on in this Godly person; I'm pretty sure that he describes logic as I understand it, then goes on to utterly fail to apply it in any way resembling either what he says or what I think is correct.

-Erasmus
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joffenz

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #27 on: February 27, 2006, 02:34:16 PM »
Quote from: "Erasmus"
Okay, so, good, I'm not out of my mind.


Course not, you're only debating whether paper exists on a website devoted to the belief that the Earth is flat...

As you said Godly appears to define logic correctly but then apply it in a contradictory way. Perhaps he means to say that it was *not* a valid argument? That would make sense, if it was a typo or something.
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thayli31285

Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #28 on: February 28, 2006, 04:01:19 PM »
This is easily the most surreal discussion I've ever stumbled upon.
Cheesejoff, Just because you make a statment doesn't make it true.  You have to come to that statment in a way that makes sense.  Setting up an esoteric loop doesn't change reality.  
Now, I freely admit to not being the most well versed in boolian algabra and the such, but I do know when an argument doesn't make sense.  And yours doesn't.  Words are just arbitrary symbols for ideas.  Ideas are abstract and do not effect the physical world, except for the actions of those capable of comprehending them.  If there is no backing for the idea, no evidence that the idea is grounded in reality, then it doesn't matter if the idea is workable or self sustaining.  It is without substance and no good for anyone.
Can you tell us how you came to your statment?  What methods did you use to connect the two?  When I read you arguments, they are focused on proving that the sentence is viable, not proving it has grounding in reality.  
I don't mean to abuse you, but this all just confuses me.  Please, respond.
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Erasmus

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Flat-Earther's, I challenge YOU to disprove this logic!
« Reply #29 on: February 28, 2006, 04:36:47 PM »
Quote from: "thayli31285"
Cheesejoff, Just because you make a statment doesn't make it true.  You have to come to that statment in a way that makes sense.  Setting up an esoteric loop doesn't change reality.


He's not trying to change reality, but rather, learn something new about it via a rational argument from agreed-upon premeses.

Quote
I do know when an argument doesn't make sense.  And yours doesn't.


So er, how do you know?

Quote
When I read you arguments, they are focused on proving that the sentence is viable, not proving it has grounding in reality.


I'm not sure that "viability" is a defined property over the set of statements.  His argument is focused on proving that the sentences is *true*.

-Erasmus
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