Question about logic
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21-02-2014, 10:26 AM (This post was last modified: 21-02-2014 10:45 AM by le_bard.)
Question about logic
"If I use logic to come up with a conclusion for what happens when I poke a balloon with a needle, am I using that same process to actually pick up a balloon and poke it with a needle? The first process (call it A) was just me thinking to myself, and the other part required me to actually do something. (call it B) Sure, thoughts were involved. I "reasoned" my way into picking up the needle and the balloon. But as I sat there, looking at the balloon and what happened to it, all my brain did was take the information my eyes were sending and going "Hey look at that, it's just as I pictured it!"

We may call both processes "reasoning" or "logic" but the point I'm making is that A and B are clearly not the same processes. Because If I thought to myself about how the world worked and, in order to see if that's how the world worked, I thought to myself about the workings of the world some more, I'd be circular indeed.

As an ending analogy, it's like doing a math problem that you don't know the answer to. If you do the problem, do you check to see if your right by doing the math problem the same exact way, over and over again? Or do you go to the back of the book and see what the answer is?"

This is a post I made about how people claim we can't use logic to prove logic. My response was to say, essentially, that we DON'T use logic to affirm logic. The process of working something out and forming a conclusion vs the process of testing that conclusion are two different things. In fact, I'm not quite sure if the latter process should even be could "logic" versus "affirmation"

However, being that we label both processes as "logic" it seems like we are totally circular.

I wanted to know how the community thinks of this, and if I'm just pulling shit out of my ass XD

It's only a debate if both parties are willing to let each other's opinions change their own.
If you aren't willing to change in light of learning more about what you fight for, what the hell are you doing expecting the other party to want to change?
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21-02-2014, 11:22 AM
RE: Question about logic
(21-02-2014 10:26 AM)le_bard Wrote:  ... If I use logic to come up with a conclusion for what happens when I poke a balloon with a needle, am I using that same process to actually pick up a balloon and poke it with a needle?
Not the same process. Direct observation/experimentation is empirical, and does not depend on inference to obtain new information. Nor does pricking a real balloon prove that the logic of your thought experiment was proper logic: the expected result could have been produced by factors totally different from the assumptions in your logic.

Logic is math. It's just a formula, like 2 + 2 = 4. And, like math, it depends on unprovable axioms as its roots. The axioms are only "proved" by experience: nothing has yet ever disproved them. Everything else is rules built up from the axioms.

No system, math or logic, can be built contradiction free. Division by zero and zero factorial = 1 are two examples of math's internal inconsistencies (by no means the only ones). But those contradictions do not cripple math's power and usefulness. The logic process is similarly very powerful and not discredited by its internal inconsistencies.

Logic and math are so powerful they are applied as proofs, not just proofs of things that can be empirically confirmed, but proofs of things that could never be empirically confirmed. Most often, empirical observation is explained via logic, not the other way around. As I said earlier, the coincidence of an empirical result matching a logical inference does not necessarily prove the logic was correct. But that doesn't invalidate logic, only that it was improperly applied.

The best argument against those who claim logic is inadequate, or has an alternative, is to show them that their very arguments against it are applied logic: they're using logic to prove that logic can't prove something. That's a contradiction that can't be overcome.
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21-02-2014, 11:41 AM
RE: Question about logic
(21-02-2014 11:22 AM)Airportkid Wrote:  
(21-02-2014 10:26 AM)le_bard Wrote:  ... If I use logic to come up with a conclusion for what happens when I poke a balloon with a needle, am I using that same process to actually pick up a balloon and poke it with a needle?
Not the same process. Direct observation/experimentation is empirical, and does not depend on inference to obtain new information. Nor does pricking a real balloon prove that the logic of your thought experiment was proper logic: the expected result could have been produced by factors totally different from the assumptions in your logic.

Logic is math. It's just a formula, like 2 + 2 = 4. And, like math, it depends on unprovable axioms as its roots. The axioms are only "proved" by experience: nothing has yet ever disproved them. Everything else is rules built up from the axioms.

No system, math or logic, can be built contradiction free. Division by zero and zero factorial = 1 are two examples of math's internal inconsistencies (by no means the only ones). But those contradictions do not cripple math's power and usefulness. The logic process is similarly very powerful and not discredited by its internal inconsistencies.

Logic and math are so powerful they are applied as proofs, not just proofs of things that can be empirically confirmed, but proofs of things that could never be empirically confirmed. Most often, empirical observation is explained via logic, not the other way around. As I said earlier, the coincidence of an empirical result matching a logical inference does not necessarily prove the logic was correct. But that doesn't invalidate logic, only that it was improperly applied.

The best argument against those who claim logic is inadequate, or has an alternative, is to show them that their very arguments against it are applied logic: they're using logic to prove that logic can't prove something. That's a contradiction that can't be overcome.

Good point, and yeah I thought about the fact that we can presuppose things falsely and still come up with a conclusion that is empirically proven. I asked the question to sye when I tried pointing out that the processes aren't the same, showing that using logic to prove logic doesn't apply in the way he tries to make it apply

It's only a debate if both parties are willing to let each other's opinions change their own.
If you aren't willing to change in light of learning more about what you fight for, what the hell are you doing expecting the other party to want to change?
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21-02-2014, 09:56 PM (This post was last modified: 21-02-2014 09:59 PM by donotwant.)
RE: Question about logic
(21-02-2014 11:22 AM)Airportkid Wrote:  Logic is math. It's just a formula, like 2 + 2 = 4. And, like math, it depends on unprovable axioms as its roots. The axioms are only "proved" by experience: nothing has yet ever disproved them. Everything else is rules built up from the axioms.

No system, math or logic, can be built contradiction free. Division by zero and zero factorial = 1 are two examples of math's internal inconsistencies (by no means the only ones). But those contradictions do not cripple math's power and usefulness. The logic process is similarly very powerful and not discredited by its internal inconsistencies.

No. Logic is based on 3 unbreakable laws of of identity, non-contradiction and excluded middle. They can be proven by absurdity of their falsehood.
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21-02-2014, 10:55 PM
RE: Question about logic
(21-02-2014 10:26 AM)le_bard Wrote:  "If I use logic to come up with a conclusion for what happens when I poke a balloon with a needle, am I using that same process to actually pick up a balloon and poke it with a needle?

Prediction involves inductive logic. Testing an induction necessarily involves more inductive and deductive logic because you are implicitly categorizing things in order to actually test the original induction and not some other induction.

Quote: The first process (call it A) was just me thinking to myself, and the other part required me to actually do something. (call it B) Sure, thoughts were involved. I "reasoned" my way into picking up the needle and the balloon. But as I sat there, looking at the balloon and what happened to it, all my brain did was take the information my eyes were sending and going "Hey look at that, it's just as I pictured it!"

Recognising a balloon, a needle and the concept of puncturing all entailed logical processes. They happened so quickly you didn't notice them but they did occur else you would have no ability to test what you intended to test.

Quote:We may call both processes "reasoning" or "logic" but the point I'm making is that A and B are clearly not the same processes. Because If I thought to myself about how the world worked and, in order to see if that's how the world worked, I thought to myself about the workings of the world some more, I'd be circular indeed.

Both processes involved reasoning, the only difference is that the latter also involved testing your inductive conclusion.

You are also taking the concept of causality for granted. The recognition of causation involves logic.

Quote:As an ending analogy, it's like doing a math problem that you don't know the answer to. If you do the problem, do you check to see if your right by doing the math problem the same exact way, over and over again? Or do you go to the back of the book and see what the answer is?"

The answer at the back of the book was obtained in the same manner that you obtained the answer. It does not represent a qualitatively different method of obtaining the answer and that is a vital point.

Quote:This is a post I made about how people claim we can't use logic to prove logic.

That is true AFAIK because it would be question begging.

Quote: My response was to say, essentially, that we DON'T use logic to affirm logic. The process of working something out and forming a conclusion vs the process of testing that conclusion are two different things.

No, testing involves induction which is a form of logic. Popping 100 balloons doesn't prove that all balloons will pop, it only support the conclusion that balloons will pop. That is the so-called problem of induction.

Also, the very act of constructing the experiment required logic. Think about it in terms of creating a robot to perform the experiment and you will see that the situation is full of logical deductions and inductions.

Quote: In fact, I'm not quite sure if the latter process should even be could "logic" versus "affirmation"

It is logic, it is inductive logic which is distinct from deductive logic. The conclusion that you form about balloons in general is an induction.

Quote:However, being that we label both processes as "logic" it seems like we are totally circular.

No they both involve logic. All rational behaviour is inescapably logical.

The broader issue which you are groping regards the ontological status of the laws of classical logic.
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21-02-2014, 11:04 PM
RE: Question about logic
(21-02-2014 11:22 AM)Airportkid Wrote:  Not the same process. Direct observation/experimentation is empirical, and does not depend on inference to obtain new information.

"[I]nference to obtain new information" does not exhaust the field. Performing the experiment and making sense of it requires logic. Recognising causality requires all sorts of deductions and inductions that you are taking for granted.

Quote: Nor does pricking a real balloon prove that the logic of your thought experiment was proper logic: the expected result could have been produced by factors totally different from the assumptions in your logic.

There is no "prove" in inductive logic, there is only "support" and the result would support his presumed inductive conclusion.

Quote:Logic is math. It's just a formula, like 2 + 2 = 4. And, like math, it depends on unprovable axioms as its roots.
The axioms are only "proved" by experience: nothing has yet ever disproved them. Everything else is rules built up from the axioms.

I think you are conflating deductive logic and inductive logic.
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21-02-2014, 11:06 PM
RE: Question about logic
Btw the zero factorial does not contradict anything here is why.
http://statistics.about.com/od/ProbHelpa...al-One.htm
Nor is division by zero.
0/0 = any number is good.
anything which is not zero / 0 = no answer will suffice.
Perfectly consistent.
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21-02-2014, 11:17 PM (This post was last modified: 21-02-2014 11:23 PM by sporehux.)
RE: Question about logic
(21-02-2014 11:06 PM)donotwant Wrote:  Btw the zero factorial does not contradict anything here is why.
http://statistics.about.com/od/ProbHelpa...al-One.htm
Nor is division by zero.
0/0 = any number is good.
anything which is not zero / 0 = no answer will suffice.
Perfectly consistent.

Materialistically its a null event, if there are no apples then its illogical to consider dividing them.

Using math to prove logic is invalid is a favorite trick a theist friend if mine throws up when science threatens his dogma.
He is yet to prove a 1=0 or 0=1 or any other shit he has claimed.

Theism is to believe what other people claim, Atheism is to ask "why should I".
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21-02-2014, 11:26 PM
RE: Question about logic
(21-02-2014 11:17 PM)sporehux Wrote:  
(21-02-2014 11:06 PM)donotwant Wrote:  Btw the zero factorial does not contradict anything here is why.
http://statistics.about.com/od/ProbHelpa...al-One.htm
Nor is division by zero.
0/0 = any number is good.
anything which is not zero / 0 = no answer will suffice.
Perfectly consistent.

Materialistically its a null event, if there are no apples then its illogical to consider dividing them.

Using math to prove logic is invalid is a favorite trick a theist friend if mine throws up when science threatens his dogma.
He is yet to prove a 1=0 or 0=1 or any other shit he has claimed.

What are you talking about? The logic arises from 3 fundamental logical policies.
And the math also stands on these 3 laws.
The proofs that 2*2=5 etc is happening precisely when logic is violated because in the expression they either take a square root out of a number or divide by zero or some other shit which violated equality. If you don't violate logic you will never prove that 1 = 0.
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22-02-2014, 01:16 AM
RE: Question about logic
(21-02-2014 09:56 PM)donotwant Wrote:  No. Logic is based on 3 unbreakable laws of of identity, non-contradiction and excluded middle. They can be proven by absurdity of their falsehood.

Yes but the OP is concerned with a justification of the three laws of classical logic and you have not provided one.

"They can be proven by absurdity of their falsehood" doesn't get you anywhere because you are appealing to induction and induction will not give you the universality that you need to justify your use of the word "proven".
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