Philosophy Now Forum

Fallacy of validity.

1. Something is determined valid if it is sound. Soundness is determined if it is rational. Rational is determined by x. X is determined by y etc.

2. Validity is defined by progressive variation.

3. Validity is invalid as there is no valid argument for it.

Eodnhoj7 wrote: ↑Wed Jan 23, 2019 5:55 pm Fallacy of validity.

1. Something is determined valid if it is sound. Soundness is determined if it is rational. Rational is determined by x. X is determined by y etc.

2. Validity is defined by progressive variation.

3. Validity is invalid as there is no valid argument for it.

I see what you are getting at, but there's a bit of a mistake. A sound argument has to be valid but a valid arg doesn't have to be sound.
Also, is it all that controversial to argue that the laws of logic are not derived through themselves?

FlashDangerpants wrote: ↑Wed Jan 23, 2019 6:08 pm

Eodnhoj7 wrote: ↑Wed Jan 23, 2019 5:55 pm Fallacy of validity.

1. Something is determined valid if it is sound. Soundness is determined if it is rational. Rational is determined by x. X is determined by y etc.

2. Validity is defined by progressive variation.

3. Validity is invalid as there is no valid argument for it.

I see what you are getting at, but there's a bit of a mistake. A sound argument has to be valid but a valid arg doesn't have to be sound.
Also, is it all that controversial to argue that the laws of logic are not derived through themselves?

Actually validity is defined through various axioms, soundness being one. In the case where an argument is valid and sound, soundness equates to validity.

I have a few threads elsewhere about the contradictory nature of the laws of logic as well as there replacements.

If the laws of logic are derived through themselves, then that means they are circular. However if they are not circular then they have no ability to exist through eachother.

Because the laws of logic exist through a circularity they are contradictory. The principle of identity as contradictory thread observes this, but the necessity of the laws cycling through eachother also observes this.

FlashDangerpants wrote: ↑Wed Jan 23, 2019 6:08 pm I see what you are getting at, but there's a bit of a mistake. A sound argument has to be valid but a valid arg doesn't have to be sound.
Also, is it all that controversial to argue that the laws of logic are not derived through themselves?

This is the problem of criterion (epistemology).

It all boils down to how you interpret this part:

an argument is logically valid if it is in principle impossible for the premises to be true and the conclusion false at the same time.

I interpret it in the strictest possible sense possible given the word impossible. Unless you think that's ambiguous?
If it said "it is highly improbable for the premises to be true and the conclusion to be false" then it would be a different matter.

I interpret it in the way that if there is ANY chance that the premises can be true, but the conclusion can be false THEN the argument is invalid.
If there is even a 1 in 10000000000000000000 chance that the premises can be true, but the conclusion can be false - then the argument is deductively invalid.

If you accept the above interpretation then all of these consequences follow:
* Deduction mandates absolute certainty as to the correctness of your conclusions.
* Any possibility of error means you are doing induction not deduction.
* With 100% certainty falsification is not possible without leading to contradictions.
* To have 100% certainty of conclusions, you must have 100% perfect knowledge about the correctness of your premises.

So basically while we live in a reality with partial knowledge we are always doing induction, even when we think we are doing deduction.

Eodnhoj7 wrote: ↑Wed Jan 23, 2019 5:55 pm Fallacy of validity. Something is determined valid if it is sound.

???
Soundness isn't a condition of validity.
Here is the definition of the logical validity of an argument:

An argument is usually said to be logically valid if all cases in which the premises are true, the conclusion is also true.
Or, equivalently, an argument is said to be valid if there is no case in which the premises are true and the conclusion is false.

I can't see any fallacy in there myself.
You think people wouldn't have spotted a fallacy if there was one since Aristotle, 2,400 years ago?
EB

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:33 pm You think people wouldn't have spotted a fallacy if there was one since Aristotle, 2,400 years ago?

We have. And we are pointing it out.

Well, mathematicians have been pointing it out for what. 300 years?

Philosophers are yet to catch a wake up call.

Logik wrote: ↑Wed Jan 23, 2019 7:54 pm * Deduction mandates absolute certainty as to the correctness of your conclusions.

No.
If the argument is valid, then if the premises are true, then it is absolutely certain that the conclusion is true.
See?
So, just because the argument is valid doesn't imply that the conclusion is true, let alone true in absolute certainty.
EB

Logik wrote: ↑Wed Jan 23, 2019 9:37 pm

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:33 pm You think people wouldn't have spotted a fallacy if there was one since Aristotle, 2,400 years ago?

We have. And we are pointing it out. Well, mathematicians have been pointing it out for what. 300 years?

Please provide an authoritative reference.
EB

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:39 pm If the argument is valid, then if the premises are true, then it is absolutely certain that the conclusion is true.
See?

OK cretin.

What happens when your "absolutely certain true conclusion" disagrees with empirical observation?

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:40 pm Please provide an authoritative reference.
EB

You want me to appeal to authority?

What an idiot.

Sure. Which authorities do you recognise?

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:40 pm Please provide an authoritative reference.
EB

Would this suffice? https://philosophynow.org/issues/46/New ... aser_Sword

And since you claim that you trust your "intuition":
https://en.wikipedia.org/wiki/Construct ... thematics)
https://en.wikipedia.org/wiki/Intuitionistic_logic

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:33 pm

Eodnhoj7 wrote: ↑Wed Jan 23, 2019 5:55 pm Fallacy of validity. Something is determined valid if it is sound.

???
Soundness isn't a condition of validity.
Here is the definition of the logical validity of an argument:

An argument is usually said to be logically valid if all cases in which the premises are true, the conclusion is also true.
Or, equivalently, an argument is said to be valid if there is no case in which the premises are true and the conclusion is false.

I can't see any fallacy in there myself.
You think people wouldn't have spotted a fallacy if there was one since Aristotle, 2,400 years ago?
EB

Aristotelian logic is a religious belief system.

"Soundness is the ability to be based on good reason or judgement".

That is the definition, approximately, based on google.

Validity, if you Google, is based on reason or fact.

Both terms are connected through reason, and hence connected to eachother as a progressive defintion of reason.

Logik wrote: ↑Wed Jan 23, 2019 9:45 pm

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:40 pm Please provide an authoritative reference.
EB

Would this suffice? https://philosophynow.org/issues/46/New ... aser_Sword

Irrelevant.
No mention of validity.
EB

Logik wrote: ↑Wed Jan 23, 2019 9:45 pm

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:40 pm Please provide an authoritative reference.
EB

And since you claim that you trust your "intuition":
https://en.wikipedia.org/wiki/Construct ... thematics)

Irrelevant.
No mention of validity.
EB

Speakpigeon wrote: ↑Wed Jan 23, 2019 10:12 pm

Logik wrote: ↑Wed Jan 23, 2019 9:45 pm

Speakpigeon wrote: ↑Wed Jan 23, 2019 9:40 pm Please provide an authoritative reference.
EB

And since you claim that you trust your "intuition":
https://en.wikipedia.org/wiki/Construct ... thematics)

Irrelevant.
No mention of validity.
EB

Do you want me to edit the wikipedia article and add the word "validity" in there, or can you actually use your own brain?