On 12/19/2023 9:55 AM, immibis wrote:
> On 12/19/23 16:22, olcott wrote:
>> A deductive argument is said to be valid if and only if it takes a form
>> that makes it impossible for the premises to be true and the conclusion
>> nevertheless to be false. https://iep.utm.edu/val-snd/
>>
>> On that basis we can conclude that this sentence is valid:
>> "Kittens are 15 story office buildings therefore water is H2O."
>>
>> When we redefine value to be a conclusion must be a necessary
>> consequence of all of its premises then the above nonsense
>> sentence is not valid.
>>
> What is a necessary consequence?
>

◊ means possibly
◻ means necessarily
¬ means not
◊P means ¬◻¬P
◻P means ¬◊¬P

A---B---A ◻ B
t---t-----t
t---f-----f
f---?-----? When A is false then we know nothing about B

> A consequence is said to be necessary if and only if it takes a form
> that makes it impossible for the antecedents to be true and the
> consequence nevertheless to be false...

--
Copyright 2023 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer

On 12/19/2023 9:55 AM, immibis wrote:
> On 12/19/23 16:22, olcott wrote:
>> A deductive argument is said to be valid if and only if it takes a form
>> that makes it impossible for the premises to be true and the conclusion
>> nevertheless to be false. https://iep.utm.edu/val-snd/
>>
>> On that basis we can conclude that this sentence is valid:
>> "Kittens are 15 story office buildings therefore water is H2O."
>>
>> When we redefine value to be a conclusion must be a necessary
>> consequence of all of its premises then the above nonsense
>> sentence is not valid.
>>
> What is a necessary consequence?
>
> A consequence is said to be necessary if and only if it takes a form
> that makes it impossible for the antecedents to be true and the
> consequence nevertheless to be false...

*This may be a more exactly precise way to say what I mean*
My correction to the notion of a valid argument means that the
truth of the conclusion depends on the truth all of the premises.

If any premise is false or irrelevant then the conclusion is not proved.
(a) I go outside
(b) I am unprotected from the rain
(c) then I get wet.

(a) I go outside
(b) I eat a popsicle
(c) Do I get wet? impossible to tell.

--
Copyright 2023 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer

On 12/19/23 10:22 AM, olcott wrote:
> On 12/19/2023 7:34 AM, immibis wrote:
>> On 12/19/23 04:02, olcott wrote:
>>> On 12/18/2023 11:37 AM, immibis wrote:
>>>> On 12/17/23 18:11, olcott wrote:
>>>>> On 12/17/2023 2:17 AM, immibis wrote:
>>>>>>
>>>>>> "The moon is made from green cheese" is a necessary consequence of
>>>>>> "all cats are dogs" and "some cats are not dogs". Or can you
>>>>>> imagine a world where all cats are dogs and some cats are not
>>>>>> dogs, but the moon isn't made from green cheese?
>>>>>
>>>>> It is not true that anything is semantically entailed by any
>>>>> contradiction. When the Principle of explosion says that everything is
>>>>> syntactically entailed by a contradiction the POE is a liar that
>>>>> denies
>>>>> the law of non-contradiction. For analytical truth coherence is the
>>>>> measure.
>>>>>
>>>>
>>>> Can you imagine a world where all cats are dogs and some cats are
>>>> not dogs, but the moon isn't made from green cheese?
>>>
>>> That would be incoherent: The coherence theory of truth applies to
>>> the analytical body of knowledge.
>>>
>> I've never heard of these two, and they seem to be fully immersed in
>> philosophy, not computer science or mathematical logic.
>
> Without Philosophy logic has no basis. The basis that logic does have is
> incoherent because they got the philosophy wrong.

Nope, Without logic, Philosophy has no basis.
>
> A deductive argument is said to be valid if and only if it takes a form
> that makes it impossible for the premises to be true and the conclusion
> nevertheless to be false. https://iep.utm.edu/val-snd/
>
> On that basis we can conclude that this sentence is valid:
> "Kittens are 15 story office buildings therefore water is H2O."

Yes. Can you show it to NOT be valid?

Is there a case where we have Kittens as 15 story office buildings and
NOT have water as H2O?

Your problem is you don't understand how logic works, and thus you don't
really understand philosophy.

>
> When we redefine value to be a conclusion must be a necessary
> consequence of all of its premises then the above nonsense
> sentence is not valid.
>

On 12/19/23 12:05 PM, olcott wrote:
> On 12/19/2023 9:55 AM, immibis wrote:
>> On 12/19/23 16:22, olcott wrote:
>>> A deductive argument is said to be valid if and only if it takes a form
>>> that makes it impossible for the premises to be true and the conclusion
>>> nevertheless to be false. https://iep.utm.edu/val-snd/
>>>
>>> On that basis we can conclude that this sentence is valid:
>>> "Kittens are 15 story office buildings therefore water is H2O."
>>>
>>> When we redefine value to be a conclusion must be a necessary
>>> consequence of all of its premises then the above nonsense
>>> sentence is not valid.
>>>
>> What is a necessary consequence?
>>
>
> ◊ means possibly
> ◻ means necessarily
> ¬ means not
> ◊P means ¬◻¬P
> ◻P means ¬◊¬P
>
> A---B---A ◻ B
> t---t-----t
> t---f-----f
> f---?-----? When A is false then we know nothing about B
>
>

In other words, your system of logic can not assign a validity to an
implication.

Note, your "conclusion" actually comes out of the normal definition of
implication, since A->B is true for A being false and B being either
True or False, then we know nothing about B.

Note, for YOUR "truth Table" if we know that A -> B is a true sttement,
then we can not determine that A is false from knowing that B is false.

You have lost the relationship that A -> B alse means that ~B -> ~A

>
>
>> A consequence is said to be necessary if and only if it takes a form
>> that makes it impossible for the antecedents to be true and the
>> consequence nevertheless to be false...
>

On 12/19/23 12:26 PM, olcott wrote:
> On 12/19/2023 9:55 AM, immibis wrote:
>> On 12/19/23 16:22, olcott wrote:
>>> A deductive argument is said to be valid if and only if it takes a form
>>> that makes it impossible for the premises to be true and the conclusion
>>> nevertheless to be false. https://iep.utm.edu/val-snd/
>>>
>>> On that basis we can conclude that this sentence is valid:
>>> "Kittens are 15 story office buildings therefore water is H2O."
>>>
>>> When we redefine value to be a conclusion must be a necessary
>>> consequence of all of its premises then the above nonsense
>>> sentence is not valid.
>>>
>> What is a necessary consequence?
>>
>> A consequence is said to be necessary if and only if it takes a form
>> that makes it impossible for the antecedents to be true and the
>> consequence nevertheless to be false...
>
> *This may be a more exactly precise way to say what I mean*
> My correction to the notion of a valid argument means that the
> truth of the conclusion depends on the truth all of the premises.
>
> If any premise is false or irrelevant then the conclusion is not proved.
> (a) I go outside
> (b) I am unprotected from the rain
> (c) then I get wet.
>
> (a) I go outside
> (b) I eat a popsicle
> (c) Do I get wet? impossible to tell.
>
>

Which means, for standard logic, your second set (where (c) makes an
actual statement about getting wet) is just a false implication an not
valid.

A & B -> C is true ONLY if any time A and B are True then C is also True.

So, a implication like

If (a) I go outside, and (b) I eat a popsicle, then (c) I get wet is
just a false implication, as there are cases where (a) and (b) are true
but (c) isn't.

Somehow you don't seem to understand that not all implications that can
be stated are true.

Note, just because ONE time I went outside and ate a popsicle I got wet,
does NOT prove that implication, as to prove it you need to be able to
look at ALL POSSIBLE cases.

But, I guess since you think proof by example is valid, I guess that
shows your problem with implication,

On 12/19/23 18:26, olcott wrote:
> *This may be a more exactly precise way to say what I mean*
> My correction to the notion of a valid argument means that the
> truth of the conclusion depends on the truth all of the premises.
>
> If any premise is false or irrelevant then the conclusion is not proved.
> (a) I go outside
> (b) I am unprotected from the rain
> (c) then I get wet.
>
> (a) I go outside
> (b) I eat a popsicle
> (c) Do I get wet? impossible to tell.
>
>

Alright so the moon being blue is a necessary consequence of me being
wet and not wet. If I'm wet and not wet, this proves the moon is blue,
we can tell that, so it's a necessary consequence.

We got quite into it here, about why
"ex falso quodlibet + material implication",
has good reasonings to put it aside.

The idea is just defining TND as a class and treating it either way, is
what it is.

The "ex falso nihilum" really much better reflects
that "non-sense is a non-starter" and
excludes "ex falso quodlibet" and
excludes "it's crazy? whatever you say, ..."
and excludes "contradicting myself, what I say, ...".

On 2/21/2024 12:13 PM, Ross Finlayson wrote:
> The idea is just defining TND as a class and treating it either way, is
> what it is.
>
> The "ex falso nihilum" really much better reflects
> that "non-sense is a non-starter" and
> excludes "ex falso quodlibet" and
> excludes "it's crazy?  whatever you say, ..."
> and excludes "contradicting myself, what I say, ...".
>

We agree that the Principle of Explosion is nonsense.

....14 Every epistemological antinomy can likewise be used for a
similar undecidability proof...(Gödel 1931:43)

I don't know if we agree that epistemological antinomy
(self-contradictory expressions) are also nonsense.

--
Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer