Definition of logical validity

[Speakpigeon]

It's fine with me, as long as you can't argue shit.
EB

[Logik]

It's fine with me, as long as you can't argue shit.
EB

Good! Stay in philosophy. Where you can will all the arguments and all the internet!

Science doesn't need any more idiots.

[surreptitious57]

the validity of an argument isnt affected by the falsification of its conclusion for example by empirical observations

A valid argument is one where the conclusion is true in relation to the premises but only within the context of the argument and nothing else
But why use an argument after its conclusion has been falsified by empiricism ? For it would serve no purpose and would therefore be useless

[surreptitious57]

We re talking about validity in this thread and your explanation here only shows how scientists get to revise
their beliefs whenever new facts come to contradict the conclusion of the theory currently accepted as science

Your hypothesis is that you are doing deduction
My hypothesis is that you SAY you are doing deduction but you are actually doing induction

He is doing induction because he is talking about science. But his language is sloppy because scientists dont have beliefs and new evidence
doesnt always contradict pre existing knowledge. Sometimes it simply adds to it without taking anything away from what is already known

[Speakpigeon]

the validity of an argument isnt affected by the falsification of its conclusion for example by empirical observations

A valid argument is one where the conclusion is true in relation to the premises but only within the context of the argument and nothing else
But why use an argument after its conclusion has been falsified by empiricism ? For it would serve no purpose and would therefore be useless

So you too you don't know what the Modus tollens is?

Modus tollens: ¬B ∧ (A → B) ⊢ ¬A

OK, may be you know about it but don't understand how it is used.
Yet, isn't that something which has to be not only very useful but also absolutely essential in the context?
EB

[Speakpigeon]

We re talking about validity in this thread and your explanation here only shows how scientists get to revise
their beliefs whenever new facts come to contradict the conclusion of the theory currently accepted as science

Your hypothesis is that you are doing deduction
My hypothesis is that you SAY you are doing deduction but you are actually doing induction

He is doing induction because he is talking about science.

Talking is nothing like doing induction.
This is just sloppy language.

But his language is sloppy because scientists dont have beliefs

My language is not "sloppy". Just because you disagree with my saying that scientists have beliefs doesn't make my language "sloppy".
Your use of "sloppy" here is sloppy.
And scientists do have beliefs.
If you think not, prove it.

and new evidence doesnt always contradict pre existing knowledge. Sometimes it simply adds to it without taking anything away from what is already known

Sometimes, sure. And sometimes, not.
EB

[Logik]

Your hypothesis is that you are doing deduction
My hypothesis is that you SAY you are doing deduction but you are actually doing induction

He is doing induction because he is talking about science.

Talking is nothing like doing induction.
This is just sloppy language.

But his language is sloppy because scientists dont have beliefs

My language is not "sloppy". Just because you disagree with my saying that scientists have beliefs doesn't make my language "sloppy".
Your use of "sloppy" here is sloppy.
And scientists do have beliefs.
If you think not, prove it.

and new evidence doesnt always contradict pre existing knowledge. Sometimes it simply adds to it without taking anything away from what is already known

Sometimes, sure. And sometimes, not.
EB

Modus Tollens doesn't solve anything, numb nuts.

If the premise is true (P)
And the argument is valid (V)
Then the conclusion is true (C)

P ∧ V ⇒ C

Write out the truth-table, cretin.

P V C
0 0 0 If the premises are false AND the argument is invalid the conclusion is false
0 1 0 If the preises are false AND the argument is valid the conclusion is false.
1 0 0 If the premises are true AND the argument is invalid the conclusion is false.
1 1 1 If the premises are true AND the argument is valid the conclusion is true.

Modus Tollens says If ¬C ⇒ ¬P. But that's incomplete!

There are THREE possible explanations for ¬C:
* P ∧ ¬V
* ¬P ∧ V
* ¬P ∧ ¬V

Modus Tollens ONLY applies IF the argument is valid.

IF the argument is invalid then the premises can be true be true.

Which is exactly what P ∧ ¬V ⇒ ¬C says!

[Speakpigeon]

Modus Tollens ONLY applies IF the argument is valid.

Sure, A → B, and that's exactly the explicit premise on which is based the Modus tollens: ¬B ∧ (A → B) ⊢ ¬A
You don't seem to get what the Modus tollens means.

Modus Tollens says If ¬C ⇒ ¬P. But that's incomplete!

No, it's definitely not what the Modus tollens says, and, yes, what you claim it says is incomplete.
You're an ignoramus. A loud and brutish ignoramus.
Look here what the Modus tollens really says: ¬B ∧ (A → B) ⊢ ¬A
You're an ignoramus. A loud and brutish ignoramus.

So, apparently, you think scientific theories may be logically not valid?!
Could you give an example of a scientific theory you think is logically not valid?
And then prove it's not valid.
Maybe start with Newton. What would have been logically not valid in Newton's Theory of Gravitation?
EB

[Logik]

So, apparently, you think scientific theories may be logically not valid?!
Could you give an example of a scientific theory you think is logically not valid?
And then prove it's not valid.
Maybe start with Newton. What would have been logically not valid in Newton's Theory of Gravitation?
EB

Oh, you seem to have switched sides all of a sudden?

Newton’s theory is inductive, not deductive. You are making my argument for me.

All scientific theories are inductive.

But... you can prove me wrong by showing me a deductively valid scientific theory.

Hint: physicists call it “the theory of everything”

[surreptitious57]

And scientists do have beliefs

They do have them but they are of zero relevance when they are actually doing science
As what they can demonstrate with evidence is what is important not what they believe

Belief is an article of faith that requires no evidence at all
Which is as far removed from science as it is possible to be

Hence why I referred to your language as sloppy which it was
So a better word to use instead of belief would be hypothesis

[surreptitious57]

What would have been logically not valid in Newtons Theory of Gravitation

General Relativity falsified the Universal Theory Of Gravitation over a hundred years ago
The fact that Newtons theory is still used today just means it has some useful application

[surreptitious57]

Could you give an example of a scientific theory you think is logically not valid

New evidence could falsify every single one of them including the most rigorous ones
Science is inductive and so deals with what is probably true not what is definitely true

Newtons Theory Of Universal Gravitation stood unquestioned for over two hundred years before General Relativity
And then until a Theory Of Quantum Gravity is discovered then GR will stand as the current best theory of its time

No theory is immune from potential falsification no matter how rigorous or extensive the supporting evidence for it is

[Logik]

Look here what the Modus tollens really says: ¬B ∧ (A → B) ⊢ ¬A

You are so fucking stupid that you can't even tell that (A → B) means exactly the same thing as I have defined V.

Let me help you out

https://en.wikipedia.org/wiki/List_of_logic_symbols

A ⇒ B is true if and only if B can be true and A can be false but not vice versa .

So in any situation in which B is false and A is true then (A ⇒ B) is false!

So ¬B ∧ (A → B) ⊢ ¬A is exactly the same thing as ¬C ∧ V ⊢ ¬P

Modus Tollens ONLY applies IF the argument is valid e.g when V is True.
Modus Tollens says nothing about situations in which V is False.

Modus Tollens is an axiomatic truism.

If you aren't going to pay me $100 for the lesson, at least pay it for the air you are stealing.

[Speakpigeon]

Modus Tollens doesn't solve anything, numb nuts.
If the premise is true (P)
And the argument is valid (V)
Then the conclusion is true (C)
P ∧ V ⇒ C
Write out the truth-table, cretin.
P V C
0 0 0 If the premises are false AND the argument is invalid the conclusion is false
0 1 0 If the preises are false AND the argument is valid the conclusion is false.
1 0 0 If the premises are true AND the argument is invalid the conclusion is false.
1 1 1 If the premises are true AND the argument is valid the conclusion is true.

No.
This proves you don't even know the truth table of the material implication.
So, here is the correction of your "truth table" completed with the three missing logical cases in bold red:

P V C
0 0 0 If the premises are false AND the argument is invalid the conclusion is false
0 1 0 If the premises are false AND the argument is valid the conclusion is false.
1 0 0 If the premises are true AND the argument is invalid the conclusion is false.
0 0 1 If the premises are false AND the argument is invalid the conclusion is true.
0 1 1 If the premises are false AND the argument is valid the conclusion is true.
1 0 1 If the premises are true AND the argument is invalid the conclusion is true.
1 1 1 If the premises are true AND the argument is valid the conclusion is true.

You are an ignoramus. A loud and abusive ignoramus.
EB

[Speakpigeon]

And scientists do have beliefs

They do have them but they are of zero relevance when they are actually doing science
As what they can demonstrate with evidence is what is important not what they believe

Belief is an article of faith that requires no evidence at all
Which is as far removed from science as it is possible to be

Hence why I referred to your language as sloppy which it was
So a better word to use instead of belief would be hypothesis

Call me on my iPhone whenever you can prove your claim that scientists don't have beliefs.
EB