circular reasoning ok sometimes?

[wakawakawaka]

now some of you might know of Jason Lisle who came up in 2010 with a paper to supposedly solve the problem of starlight and YEC, but something else he said also was interesting to say the least- he claimed that there are times when its perfectly okay to use circular reasoning! he claimed that you must assume logic to prove logic ,so then is it true? are there times when its okay to use circular reasoning?

 

[wakawakawaka]

anyways here is also his blog feel free to take a look at his "reasoning" and "logic http://www.jasonlisle.com/

 

[gnome]

I would argue that for logic to arrive at a useful conclusion, you must start with at least some agreed upon axioms.

The very idea of using reason isn't a step in logical reasoning.

 

[Brian-M]

he claimed that you must assume logic to prove logic

You don't assume logic to prove logic. You prove logic by empiricism. In other words, you test it against the real world to see if it actually works.

Although, it is possible to prove new logical axioms by applying existing tested logic.

 

[Kopji]

If his example, which for all I can tell seems to be - is that the Bible is true because it says everything in it is true, and therefore it is true. Then no. Circular logic is a fail.

His site actually makes me sad that a bright and otherwise promising mind is so easily deluded by nonsense. His so called epistemology cannot even tell me with any assurance that the universe was not created five minutes ago, just made to look old.

The emperor has no clothes.

 

[theprestige]

You don't assume logic to prove logic. You prove logic by empiricism. In other words, you test it against the real world to see if it actually works.

You've not dealt much with pure maths, have you?

 

[barehl]

His so called epistemology cannot even tell me with any assurance that the universe was not created five minutes ago, just made to look old.

Psalm 33:4
For the word of the Lord is right; and all his works are done in truth.

Proverbs 11:18
The wicked worketh a deceitful work

Malachi 1:14
But cursed be the deceiver


Making the world look old when it was not would be a deceitful work and therefore wicked. A work done in truth would be as it appears.

 

[Brainiac2]

Psalm 33:4
For the word of the Lord is right; and all his works are done in truth.

Proverbs 11:18
The wicked worketh a deceitful work

Malachi 1:14
But cursed be the deceiver


Making the world look old when it was not would be a deceitful work and therefore wicked. A work done in truth would be as it appears.

Sounds like Cartesian logic.

 

[Brainache]

Psalm 33:4
For the word of the Lord is right; and all his works are done in truth.

Proverbs 11:18
The wicked worketh a deceitful work

Malachi 1:14
But cursed be the deceiver


Making the world look old when it was not would be a deceitful work and therefore wicked. A work done in truth would be as it appears.

I never thought I'd see a Biblical demonstration of the non-existence of its own God, but now I have. Thank you.

We have a Universe which, when you look closely, directly contradicts all of the nonsense asserted about it in the Bible. So the Bible is a work of deception. It cannot be the product of a truthful God.

Sorry to have to break it to you guys, but it really does appear that the bible was written by ordinary people who had no idea about how the world actually works.

 

[Brian-M]

You've not dealt much with pure maths, have you?

No, so I could be wrong.

But you can empirically demonstrate basic arithmetic quite easily. If you want to demonstrat that two plus two equals four, you just put two objects in a container, add two more objects, then add them up. You can demonstrate things like cube roots a similar way. You can prove that the cube root of styrofoam is three by sticking toothpicks in twenty-seven styrofoam balls to build a 3x3x3 cube. You can demonstrate things like calculus with analog devices that use physical material, such as water.

Even more abstract things have real-world applications. For example, imaginary numbers. When you're calculating the impedance in an AC circuit you use real numbers for resistance and the Y-axis imaginary numbers for reactance. And it works. You know the logic of imaginary numbers is valid because the logic applies in real-world situations.

Even abstracts with no direct real-world applications can be tested by or applied to logic which has either been tested directly in reality or tested by other logic which has itself been tested in some way.

Or can you give me examples of instances of pure maths that are conceptual islands, that does not utilize logic that can be verified by being applied, either directly or indirectly, in real-world situations to see if it holds true?

 

[Beelzebuddy]

Circular reasoning is a fantastic tool for approaching those applications that can be approached with circular reasoning.

Although, it is possible to prove new logical axioms by applying existing tested logic.

Which it's then important to verify with empirical evidence.

 

[I Am The Scum]

You don't assume logic to prove logic. You prove logic by empiricism. In other words, you test it against the real world to see if it actually works.

Although, it is possible to prove new logical axioms by applying existing tested logic.

I would disagree with this. It is important to remember that logic, in its most basic form, only concerns itself with how certain propositional forms must necessarily lead to other forms. For example:

If A is true, then B is true.
A is true.
Therefore, B is true.

A and B do not have any referents, so there is no way you can possibly verify any of this empirically. However, it is logically valid.

 

[aggle-rithm]

When Cepheid variables were first discovered, scientists used something akin to circular reasoning to take a stab at how far away certain stars were. The problem up until then was that a star's brightness was a function of both its size and its distance, so there was no way to separate one from the other. The discovery that some stars pulsed in a way that indicated its size helped us solve some of the puzzle, but before more information was available they had to make certain assumptions about the relationship between pulse rate and size...it's this far away, so we know this pulse rate means it's this big. And we know it's this big because it's this far away.

As more information filtered in, we got more and more accurate at judging distance.

IIRC.

 

[phiwum]

now some of you might know of Jason Lisle who came up in 2010 with a paper to supposedly solve the problem of starlight and YEC, but something else he said also was interesting to say the least- he claimed that there are times when its perfectly okay to use circular reasoning! he claimed that you must assume logic to prove logic ,so then is it true? are there times when its okay to use circular reasoning?

This is not quite what you ask. I certainly won't discuss "proving logic", a phrase which has no clear meaning to me.

There are times when what appears to be a circular definition is not problematic. Consider the concept of a stream of natural numbers. It is an endless sequence of naturals. To put it another way, when we take the head off the stream, we are left with another stream.

Thus, one may reasonably define a stream over N as an ordered pair <n,s> where n is in N and s is a stream over N.

That definition is obviously circular, but if we interpret it in terms of the greatest fixed point of an operator (which is implicitly identified in the definition), we find that the result is well-defined and precisely what we want.

So, sometimes, circularity in definitions is not so nonsensical as it first appears.

 

[phiwum]

You don't assume logic to prove logic. You prove logic by empiricism. In other words, you test it against the real world to see if it actually works.

Although, it is possible to prove new logical axioms by applying existing tested logic.

So, you're happy to accept the axioms and rules of inference of logic as merely very, very likely to be true?

After all, as we know, induction (i.e., appeal to experience) yields merely probable, not certain, conclusions. So, you accept the claim that, "It is very, very likely, almost but not quite certain, that '(P and Q) implies P' is true?"

Because I find that rather more certain than almost certain.

 

[wakawakawaka]

well here here is a "trilemma" from Lisle i think you guys will find it well...... head scratching
What is your answer to the trilemma? (A) logic is unjustified (accepted by blind faith). (B) logic is justified by something illogical (irrational). (C) Logic is justified by logic (circular). What is your answer?

 

[Brainiac2]

I never thought I'd see a Biblical demonstration of the non-existence of its own God, but now I have. Thank you.

We have a Universe which, when you look closely, directly contradicts all of the nonsense asserted about it in the Bible. So the Bible is a work of deception. It cannot be the product of a truthful God.

Sorry to have to break it to you guys, but it really does appear that the bible was written by ordinary people who had no idea about how the world actually works.

We have a Universe which, when you look closely, directly contradicts all of the nonsense asserted about it in the Bible.

Can you please provide an example of at least one such nonsense.

Sorry to have to break it to you guys, but it really does appear that the bible was written by ordinary people ...

Well, it provides us with a list of names of peaple wrote it. Of course some might have emplyed scribes to write as they dictated. Were they all ordinary?

or·di·nar·y
ˈôrdnˌerē/Submit
adjective
1.
with no special or distinctive features; normal.
"he sets out to depict ordinary people"
synonyms: usual, normal, standard, typical, common, customary, habitual, everyday, regular, routine, day-to-day More
antonyms: abnormal
uninteresting; commonplace.
"ordinary items of everyday wear"


synonyms: average, normal, run-of-the-mill, standard, typical, middle-of-the-road, conventional, unremarkable, unexceptional, workaday, undistinguished, nondescript, colorless, commonplace, humdrum, mundane, unmemorable, pedestrian, prosaic, quotidian, uninteresting, uneventful, dull, boring, bland, suburban, hackneyed, garden-variety; More
antonyms: unusual, exceptional
2.


https://www.google.com/#q=ordinary+definition

Let’s go with what is commonplace.

synonyms: average, normal, run-of-the-mill, standard, typical, middle-of-the-road, conventional, unremarkable, unexceptional, workaday, undistinguished, nondescript, colorless, commonplace, humdrum, mundane, unmemorable, pedestrian, prosaic, quotidian, uninteresting, uneventful, dull, boring, bland, suburban, hackneyed, garden-variety; More


antonyms: unusual, exceptional


2.

unremarkable, unexceptional,

Are kings commonplace? Solomon and David were both kings and the books attributed to them are Psalms, Ecclesiastes, Proverbs, Song of Solomon.

Were people raised in Pharoah’s family and educated there commonplace?

Moses was and the books attributed to him are Genesis, Exodus, Leviticus, Numbers Deuteronomy.

Luke was a 1st-century physician.
Were 1st century physicians commonplace?
The books he wrote are Luke and Acts.


I fail to see how such people were or are commonplace

...who had no idea about how the world actually works.

How is how the world works relevant to the biblical salvation-of-mankind-via- a- Ransom Sacrifice theme? Just curious to see how you attempt to conjoin them.

 

[I Am The Scum]

It seems pretty obvious to me that he meant "ordinary" in contrast to the idea that the Bible was written by some kind of deity or the direct agents thereof.

But don't let that fact impede some pointless nitpicking.

 

[Navigator]

We have a Universe which, when you look closely, directly contradicts all of the nonsense asserted about it in the Bible. So the Bible is a work of deception. It cannot be the product of a truthful God.

^This.

 

[Slowvehicle]

Can you please provide an example of at least one such nonsense.

You may have missed post #7.

http://www.internationalskeptics.com/forums/showthread.php?postid=9542326#post9542326

Well, it provides us with a list of names of peaple wrote it. Of course some might have emplyed scribes to write as they dictated. Were they all ordinary?

You must have missed a plethora of posts about the veracity and authenticity of biblical claims.
At best, the sectrially redacted, inconsistently edited, collection of bronze-ag superstitions known as the bible claims that certain people wrote certain parts, which can be manifestly demonstrated to be incorrect (as Moses, for instance, is supposed to have written the account of his own death...).

Let’s go with what is commonplace.

Are kings commonplace? Solomon and David were both kings and the books attributed to them are Psalms, Ecclesiastes, Proverbs, Song of Solomon.

And, of course, there is little or no historical verification that Solomon existed, or that David is any more an accurate historical figure than Arthur is...

Were people raised in Pharoah’s family and educated there commonplace?

Equally, there is no reliable evidence that the israelites were ever in Egypt, much less that milliions of them gutted Egypt's economy on their way out...

Moses was and the books attributed to him are Genesis, Exodus, Leviticus, Numbers Deuteronomy.

So the contradictions in those books are Moses' fault? Wat about the parts that speak aboput what happened after his own death?

Luke was a 1st-century physician.
Were 1st century physicians commonplace?
The books he wrote are Luke and Acts.

Definitely missed a few threads.

I fail to see how such people were or are commonplace

Before you can judge whether they were "commonplace" or not, it might be useful to demonstrate that they actually existed...

How is how the world works relevant to the biblical salvation-of-mankind-via- a- Ransom Sacrifice theme? Just curious to see how you attempt to conjoin them.

Well, many if not all of the pivotal biblical claims have no historical support in reality at all.

And, as has been said here before, "Let me save you from what I'll do to you if you don't let me 'save' you" is a protection racket, not an illustration of "divine" beneficence.

You simply cannot use the claims in the bible to indicate that the claims in the bible are true...that is the nature of the fallacy of circular reasoning: "It's true because it's in the bible because the bible says what's in the bible is true..."