An adventure in logic!

[hasone]

My logic-fu is weak, and I wish to improve it. If you are willing to help me, please evaluate the following statements:

1) God exists
2) God can write
3) The Bible was written

Thus:

4) The Bible was written by God

Does the conclusion follow from the premises?

1) Fermat wrote Fermat's Last Theorem
2) Fermat stated he had a marvelous proof of Fermat's Last Theorem
3) Fermat's Last Theorem is true
4) I have yet to use Fermat's Last Theorem in a meaningful proof

Thus:

5) Fermat's marvelous proof of Fermat's Last Theorem was a correct proof of Fermat's Last Theorem
6) I'm going to eventually use Fermat's Last Theorem in a meaningful proof, by golly, even if it's the last thing I do

Does the conclusion follow from the premises?

1) If evolution occurs, then God exists
2) Evolution occurs

Thus:

3) God exists

(D)oes (t)he (c)onclusion (f)ollow (f)rom (t)he (p)remises?

1) If a theory contradicts the Bible, it is false.
2) Evolutionary theory contradicts the Bible.

Thus

3) Evolutionary theory is false.

DTCFFTP?

1) There is a natural explanation for every phenomenon

Thus:

2) There is no supernatural explanation for any phenomena

DTCFFTP?

1) If a statement appears in KJV1611, it is true
2) Statement X is a statement
3) Statement X appears in KJV1611

Thus:

4) Statement X is true

DTCFFTP?


1) Anything not said in the Bible is not true
2) "The Earth was created approximately 6,000 years ago" was not said in the Bible
3)"christianforums.com is an internet forum" was not said in the Bible

Thus:

4) "The Earth was created approximately 6,000 years ago" is not true
5) "christianforums.com is an internet forum" is not true

DTCFFTP?

Thank you for your time.

 

[plindboe]

My logic-fu is weak, and I wish to improve it. If you are willing to help me, please evaluate the following statements:

1) God exists
2) God can write
3) The Bible was written

Thus:

4) The Bible was written by God

Does the conclusion follow from the premises?

No.

1) Fermat wrote Fermat's Last Theorem
2) Fermat stated he had a marvelous proof of Fermat's Last Theorem
3) Fermat's Last Theorem is true
4) I have yet to use Fermat's Last Theorem in a meaningful proof

Thus:

5) Fermat's marvelous proof of Fermat's Last Theorem was a correct proof of Fermat's Last Theorem
6) I'm going to eventually use Fermat's Last Theorem in a meaningful proof, by golly, even if it's the last thing I do

Does the conclusion follow from the premises?

No.

1) If evolution occurs, then God exists
2) Evolution occurs

Thus:

3) God exists

(D)oes (t)he (c)onclusion (f)ollow (f)rom (t)he (p)remises?

Yes.

1) If a theory contradicts the Bible, it is false.
2) Evolutionary theory contradicts the Bible.

Thus

3) Evolutionary theory is false.

DTCFFTP?

Yes.

1) There is a natural explanation for every phenomenon

Thus:

2) There is no supernatural explanation for any phenomena

DTCFFTP?

Depends on how you define "explanation". If a false explanation is still an explanation, then it doesn't follow logically.

1) If a statement appears in KJV1611, it is true
2) Statement X is a statement
3) Statement X appears in KJV1611

Thus:

4) Statement X is true

DTCFFTP?

Yes.

1) If a statement appears in KJV1611 but not in the journal Nature, it is false
2) Statement
Thus:

5) Statement X is false.

DTCFFTP?

Think this one misses some premises.

1) Anything not said in the Bible is not true
2) "The Earth was created approximately 6,000 years ago" was not said in the Bible
3)"christianforums.com is an internet forum" was not said in the Bible

Thus:

3) "The Earth was created approximately 6,000 years ago" is not true
4) "christianforums.com is an internet forum" is false

DTCFFTP?

Yes.

Thank you for your time.

No problem. Hope I read them all correctly.

If you need me to elaborate on any, feel free to ask.

Peter

 

[Mr. Pedantic]

My logic-fu is weak, and I wish to improve it. If you are willing to help me, please evaluate the following statements:

1) God exists
2) God can write
3) The Bible was written

Thus:

4) The Bible was written by God

Does the conclusion follow from the premises?

First, P1 is a false premise, because it cannot be suitably established that God, in fact, does exist. However, even if the first premise is true, the argument commits the fallacy of affirming the consequent; the Bible need not necessarily be written by God, even if God can write, and even if (going outside the stated argument a bit here) it says it is.

1) Fermat wrote Fermat's Last Theorem

2) Fermat stated he had a marvelous proof of Fermat's Last Theorem
3) Fermat's Last Theorem is true
4) I have yet to use Fermat's Last Theorem in a meaningful proof

Thus:

5) Fermat's marvelous proof of Fermat's Last Theorem was a correct proof of Fermat's Last Theorem
6) I'm going to eventually use Fermat's Last Theorem in a meaningful proof, by golly, even if it's the last thing I do

Does the conclusion follow from the premises?

This is also not a good argument. The premises really have nothing significant to do with each other, or the conclusions (only saying 'nothing significant' because everything has something to do with everything else, even by the most tenuous link).

1) If evolution occurs, then God exists
2) Evolution occurs

Thus:

3) God exists

(D)oes (t)he (c)onclusion (f)ollow (f)rom (t)he (p)remises?

Logically good, materially, not so good.

1) If a theory contradicts the Bible, it is false.
2) Evolutionary theory contradicts the Bible.

Thus

3) Evolutionary theory is false.

DTCFFTP?

Again, logically good, materially bad.

1) There is a natural explanation for every phenomenon

Thus:

2) There is no supernatural explanation for any phenomena

DTCFFTP?

Logically bad and materially bad. First, it cannot be proven that there is a natural explanation for every phenomenon, even if it is the most logical assumption to make regarding the explanations of various phenomena. Also, it is possible to provide a supernatural explanation for something that already has a natural 'explanation'.

1) If a statement appears in KJV1611, it is true
2) Statement X is a statement

3) Statement X appears in KJV1611

Thus:

4) Statement X is true

DTCFFTP?

Logically good, materially bad.

1) If a statement appears in KJV1611 but not in the journal

Nature, it is false
2) Statement
Thus:

5) Statement X is false.

DTCFFTP?

Logically bad and materially bad. You have not made any qualities of Statement available; therefore, there is insufficient evidence; this is both a material and logical failing. Also, however, the first premise is debatable, for many reasons regarding the completeness of the respective repositories of human knowledge, their overlapping domains, and the rigor with which statements made in those respective works are tested and against what criteria.

1) Anything not said in the Bible is not true
2) "The Earth was created approximately 6,000 years ago" was not said in the Bible
3)"christianforums.com is an internet forum" was not said in the Bible

Thus:

3) "The Earth was created approximately 6,000 years ago" is not true
4) "christianforums.com is an internet forum" is false

DTCFFTP? Thank you for your time.

Logically good, materially bad. This is because of the way things can be worded. For example, what if the Bible says "The Earth was created exactly 6,000 years ago"? According to this argument it still does not mean this statement is necessarily true, but it also means that the premises cannot now entail C3, because the definition of 'exactly' is more precise than 'approximately'.

 

[hasone]

Depends on how you define "explanation". If a false explanation is still an explanation, then it doesn't follow logically.

Since quotes don't nest, I'll reiterate the statement

1) There is a natural explanation for every phenomenon

Thus:

2) There are no supernatural explanation for any phenomena

I feel my logic-fu is weakest with this one here - this statement seems to be doing too many things at once and is thus difficult to evaluate. yea/nay?

edit: reading mr. pedantic, he seems to evaluate it just fine.

Think this one misses some premises.

It most certainly does! I meant to erase it and didn't do the job right. First post edited.

 

[plindboe]

Since quotes don't nest, I'll reiterate the statement

1) There is a natural explanation for every phenomenon

Thus:

2) There are no supernatural explanation for any phenomena

I feel my logic-fu is weakest with this one here - this statement seems to be doing too many things at once and is thus difficult to evaluate. yea/nay?

The yea or nay depends on what you mean by the word "explanation", because if the definition is independent of truth value, then a phenonemon might have a true natural explanation and also an infinite number of false supernatural explanations, i.e. the conclusion doesn't follow. Also, multiple true explanations might apply to a phenonemon, so having one true explanation doesn't rule out others. So for the logic to be valid, "explanation" will have to be defined as both true and comprehensive.

But given a less extreme definition of the word it would be a nay.

Peter

 

[Wiccan_Child]

Most of these logical statements are built on unsound premises, so their validity is moot. In any case, plindboe's post pretty much hits the nail on the head, so I won't repeat what he wrote.

 

[FrenchyBearpaw]

God is love.
Love is blind.
Ray Charles is blind.

Thus:

Ray Charles is god.

 

[Cabal]

God is love.
Love is blind.
Ray Charles is blind.

Thus:

Ray Charles is god.

Works for me.

Still better than those Christian math-ish proofs you see floating around sometimes that are just loltastic, like the trinity being 1+1+1 = 1 and that atheism is 0 x 0 = 1 or somesuch.

 

[FrenchyBearpaw]

Works for me.

Still better than those Christian math-ish proofs you see floating around sometimes that are just loltastic, like the trinity being 1+1+1 = 1 and that atheism is 0 x 0 = 1 or somesuch.

Or the ... "Pluto doesn't crash into other planets... ergo god!"

Critical Thinking Menu

 

[Cabal]

I watched the infamous Bill O'Reilly video about the tides the other day, and his followup segment where he just makes an even bigger clown of himself, and I think I was herniating by the end of it.

 

[FrenchyBearpaw]

I watched the infamous Bill O'Reilly video about the tides the other day, and his followup segment where he just makes an even bigger clown of himself, and I think I was herniating by the end of it.

Classic! "Tide goes in, tide goes out. Never a miscommunication."

skip to 1:47
http://www.youtube.com/watch?v=2BCipg71LbI

 

[hasone]

Most of these logical statements are built on unsound premises, so their validity is moot. In any case, plindboe's post pretty much hits the nail on the head, so I won't repeat what he wrote.

Aha! I think I have found the key to improving my logic-fu.

I agree that the premises are weak. I don't know why I agree besides "I disagree with them"

"God exists" seems a weak premise. But how do I establish that? "There's no evidence" seems like something of a start, but how do I evaluate whether or not something is evidence for God from a formal perspective?

Is it because "God exists" is what many times we want to prove or disprove, and it thus makes a weak premise? How would I say that formally?

A premise is sounder than "God exists" if ...?

 

[variant]

Aha! I think I have found the key to improving my logic-fu.

I agree that the premises are weak. I don't know why I agree besides "I disagree with them"

"God exists" seems a weak premise. But how do I establish that? "There's no evidence" seems like something of a start, but how do I evaluate whether or not something is evidence for God from a formal perspective?

Is it because "God exists" is what many times we want to prove or disprove, and it thus makes a weak premise? How would I say that formally?

A premise is sounder than "God exists" if ...?

Generally you want to pick premises that are hard to argue with if you want a convincing argument.

 

[hasone]

Generally you want to pick premises that are hard to argue with if you want a convincing argument.

A premise is sound enough if my debate partner(s) accept them? The soundest premise is the one everyone accepts?

 

[variant]

A premise is sound enough if my debate partner(s) accept them? The soundest premise is the one everyone accepts?

Yes, generally, If you are arguing to convince people.

If you are constructing logical proofs for other reasons I would stick with what is most evidently true.

The two should be remarkably similar but people can be.... well people.

 

[Mr. Pedantic]

A premise is sound enough if my debate partner(s) accept them? The soundest premise is the one everyone accepts?

Not all premises that are sound are accepted by everyone, and not all accepted premises are sound. The soundness of a premise is based on the evidence that can be mustered in support of it, rather than how many people accept it; that is just an argument ad populi.

 

[hasone]

Not all premises that are sound are accepted by everyone, and not all accepted premises are sound. The soundness of a premise is based on the evidence that can be mustered in support of it, rather than how many people accept it; that is just an argument ad populi.

Oh no, just when I thought my logic-fu was growing stronger

How, then, do we evaluate evidence?

 

[Mr. Pedantic]

Strength of evidence depends on several things.

Prior plausibility of the claim is important; something that seems likely based on what we already know is more plausible than something that, as far as our knowledge of the universe goes, is impossible. For example, saying that you built an internal combustion engine is more plausible than saying that you built a free energy or perpetual motion machine.

The quality of the evidence is important too. Anecdotal evidence, or hearsay, is one of the lowest forms of evidence; it can be used in the support of mundane claims, like claiming the Sun rose this morning because you saw it. However, saying "I'm going to treat my cancer with homeopathy instead of chemotherapy because my friend did it and s/he was successful", or saying "God exists because he spoke to me" is pretty much worthless. The anecdotes of multiple people affirming the same thing completely independently is stronger than the anecdote of one person, but not by much; the same faults that make single anecdotes unreliable also apply to mass anecdotes. Whereas (for example, in medicine) a large, double-blinded, placebo-controlled trial has a lot more going for it in terms of rigor, and an entire literature showing a general consensus is better still. Pictures and video used to be reliable, but because of Photoshop and other computer manipulation software, they're increasingly unreliable; anything can be faked these days. Going in this vein, the amount of evidence should also be taken into account.

 

[sfs]

Strength of evidence depends on several things.

Prior plausibility of the claim is important; something that seems likely based on what we already know is more plausible than something that, as far as our knowledge of the universe goes, is impossible. For example, saying that you built an internal combustion engine is more plausible than saying that you built a free energy or perpetual motion machine.

Prior plausibility (prior probability, in a Bayesian formulation) affects the confidence of a conclusion, not the strength of the evidence for it.

 

[hasone]

anecdotes != strong evidence.
I believe my logic-fu has leveled up ! I am now at logic level (very low plus one).

I'm going to go into the logical foundations of mathematics, and the reasons espoused for choosing first order logic (over propositional and second order logic) and the ZFC axioms, both currently and historically. I'll see if I can't come up with any good questions from there.