POLL 3 on the validity of a simple argument on Joe the Squid

[Arising_uk]

That's how I would formalise the argument:

P1 S → ¬G
P2 G → ¬E
P3 E → ¬S
P4 J → (S ⊻ G)
P5 J → E
C J → S

That's the simple way to do it but you can also use predicate logic as you did in your first formalisation here.
EB

You mean 'this's how I would formalise the argument:' ?

If so, just to check, is the disjunction inclusive or exclusive?
p.s.
Not that it matters tho' as I think this not a good formalization of your premises as whilst 'a squid' might not be a giraffe some other squid could be and this applies to all your premises and I doubt this is what you are asserting? It seems more likely you are saying that 'for any' or 'all' squids they are not giraffes. So could you choose or create a formalized quantified version of your argument please or else choose one of mine then I can test whether your argument is valid or not.
p.p.s
Although just for forms sake I think the above is a valid argument form as by truth table analysis there is n case where all the premises are true and the conclusion false.

[Speakpigeon]

That's how I would formalise the argument:

P1 S → ¬G
P2 G → ¬E
P3 E → ¬S
P4 J → (S ⊻ G)
P5 J → E
C J → S

That's the simple way to do it but you can also use predicate logic as you did in your first formalisation here.
EB

You mean 'this's how I would formalise the argument:' ?
If so, just to check, is the disjunction inclusive or exclusive?

Either ... or.

p.s.
Not that it matters tho' as I think this not a good formalization of your premises as whilst 'a squid' might not be a giraffe some other squid could be and this applies to all your premises and I doubt this is what you are asserting? It seems more likely you are saying that 'for any' or 'all' squids they are not giraffes.

So you're saying proposition logic doesn't work?!

So could you choose or create a formalized quantified version of your argument please or else choose one of mine then I can test whether your argument is valid or not.

Yours was OK, the first one.
You asked me how I'd do it. I replied and said "you can also use predicate logic as you did in your first formalisation here".
That should have been enough, I think.

p.p.s
Although just for forms sake I think the above is a valid argument form as by truth table analysis there is n case where all the premises are true and the conclusion false.

OK, and intuitively too, you think it's valid?
EB

[Speakpigeon]

P4 J → (S ⊻ G)
P5 J → E

Your system is inconsistent.
The above implies E ⇔ (S ⊻ G)
WAT?

Whatever, the question is, does that make the argument valid or invalid?
EB

[Logik]

Whatever, the question is, does that make the argument valid or invalid?

You are the only one who can answer that.

You understand the semantics of your argument. We don't.

[Arising_uk]

Either ... or. ...

Thank you.

So you're saying proposition logic doesn't work?!

Propositional logic(PL) works just fine but in this case it is not applicable as the argument you put forward is using classes, the class of squids, elephants, etc and is talking about an individual, 'Joe', i.e. in the class of 'persons' and as such needs to be formalized with quantifiers so Predicate Logic is the correct logic to use in this case. To explain a little more take your formalization,

P1 S → ¬G
P2 G → ¬E
P3 E → ¬S
P4 J → (S ⊻ G)
P5 J → E
C J → S

It doesn't work because S is not representing a proposition it just says 'a squid' and in PL the variable has to represent a proposition and this applies to the rest of your premises. This is why Predicate Logic was developed, to deal with propositions that talk about all or some members of classes.

Yours was OK, the first one.
You asked me how I'd do it. I replied and said "you can also use predicate logic as you did in your first formalisation here".
That should have been enough, I think. ...

Fair enough, might have been easier if you'd just said formalization 1. tho'.

OK, and intuitively too, you think it's valid?
EB

Why would I use 'intuition' when I have the logical methods developed by Philosophy to discover whether an argument form is valid or invalid?

[Speakpigeon]

OK, and intuitively too, you think it's valid?

Why would I use 'intuition' when I have the logical methods developed by Philosophy

So, because there are cars you've stopped walking?

the logical methods developed by Philosophy

Developed by philosophy? It was developed essentially by Boole, Frege and Russell. I think they worked more as mathematicians than philosophers.
EB

[Arising_uk]

So, because there are cars you've stopped walking?

Horses for courses.

Developed by philosophy? It was developed essentially by Boole, Frege and Russell. I think they worked more as mathematicians than philosophers.
EB

Boole was a mathematician but was also a philosopher of mind, Frege was a philosopher of mathematics and language and Russell was a philosopher of politics, mathematics, epistemology, ethics and language and a metaphysician to boot, they were all logicians and Logic is pretty much the only thing that Philosophy can call its own. The latter two pretty much created the school of Analytical Philosophy, so yes, developed by Philosophy. Although there should be a shout out to Leibniz here.

[Logik]

Logic is pretty much the only thing that Philosophy can call its own.

Alan Turing and Alonzo Church (and all of computer science) smirk at this.

The only thing Philosophy can call its own is sophistry.

[Arising_uk]

Alan Turing and Alonzo Church (and all of computer science) smirk at this.

The only thing Philosophy can call its own is sophistry.

I guess Imperial College shouldn't have taken me on for their MSc in Foundations of Advanced I.T. then.

Church was a professor of Mathematics and Philosophy.

[Logik]

Alan Turing and Alonzo Church (and all of computer science) smirk at this.

The only thing Philosophy can call its own is sophistry.

I guess Imperial College shouldn't have taken me on for their MSc in Foundations of Advanced I.T. then.

Church was a professor of Mathematics and Philosophy.

Depending on your broadness or narrowness of your definition of "Philosophy".

To call Church a philosopher is to put him in the same basket as Hegel or Nietzsche.

Just like "natural philosophy" became physics and no physicist would take the title of philosopher without being offended.

In 2019 nomenclature that which Church did which you call "Philosophy" is computer science. The field has acquired far more clarity, precision, focus and broad acceptance than a mere fringe of philosophical enquiry.

His work was useful. It produced broadly and generally re-usable tools. Arguably - digital physics was his fault.

[Arising_uk]

Depending on your broadness or narrowness of your definition of "Philosophy". ...

I was taught within the Anglo-American tradition of Analytic Philosophy(although I bucked the trend at the time and took Continental Philosophy as well) so I'm with Russell, Wittgenstein, Ayer, et al, so think a fair definition of 'Philosophy' is the aim or process of the logical clarification of thoughts or ideas.

To call Church a philosopher is to put him in the same basket as Hegel or Nietzsche. ...

I'm always amazed that reasonably educated people appear to have no idea of the Anglo-American school of Philosophy and think Continental when they think of it.

Just like "natural philosophy" became physics and no physicist would take the title of philosopher without being offended.

Natural Philosophy became many subjects not just Physics as it was a school of thought.

Given my definition of Philosophy I think pretty much anyone who becomes and expert in their field sooner or later philosophises about it, Church discussed nominalism, realism, etc with respect to his field so was doing philosophy. Frege, et al, did metaphysics. The difference between those that do it well and those who don't is that those who do it well have also bothered to read what Philosophy has said in the past.

In 2019 nomenclature that which Church did which you call "Philosophy" is computer science. The field has acquired far more clarity, precision, focus and broad acceptance than a mere fringe of philosophical enquiry. ...

Which 'mere fringe' and what 'broad acceptance' are you referring to?

His work was useful. It produced broadly and generally re-usable tools. Arguably - digital physics was his fault.

It's arguable that Zuse was the father of Digital Physics which ironically enough given this conversation is a metaphysic.

[Logik]

Depending on your broadness or narrowness of your definition of "Philosophy". ...

I was taught within the Anglo-American tradition of Analytic Philosophy(although I bucked the trend at the time and took Continental Philosophy as well) so I'm with Russell, Wittgenstein, Ayer, et al, so think a fair definition of 'Philosophy' is the aim or process of the logical clarification of thoughts or ideas.

The problem with your definition of philosophy is that it comes THAT close to defining itself, but not close enough.
How do you determine if you have clarified your thoughts/ideas sufficiently?

This is the "criterion" problem in epistemology.

With Lambda calculus - you don't have to. Because Lambda calculus produces behaviouristic models.

You don't ask whether your idea is clearly explained. You ask whether your model behaves as expected.

It's arguable that Zuse was the father of Digital Physics which ironically enough given this conversation is a metaphysic.

You are falling for the trap of linguistics again. Is there a logic that is NOT a metaphysic? If you can't classify some logics as NOT being metaphysics then you've invented a truism.

For the purpose of debate ALL logic is metaphysics.

First order logic is metaphysics.
High order logic is metaphysics also.

The difference is that one is like LEGO for 3-5 year olds, and the other is like a lego for grown ups.

Flexibility, scale and complexity are the distinguishing marks of Lambda calculus. You can invent your own LEGO bricks.

[Speakpigeon]

Boole was a mathematician but was also a philosopher of mind, Frege was a philosopher of mathematics and language and Russell was a philosopher of politics, mathematics, epistemology, ethics and language and a metaphysician to boot, they were all logicians

They tried to develop a mathematical method of formal logic and failed. All they could produce was the aptly named "1st order logic" as it is at best a 1st order approximation. In so doing, they behaved essentially as mathematicians, and not as philosophers or logicians.

Logic is pretty much the only thing that Philosophy can call its own.

Well, as far as I know, pretty much all of the current philosophy of logic defers to mathematical logic. The only actual logic left is the study of Aristotle, the Stoics and Scholastics.

The latter two pretty much created the school of Analytical Philosophy, so yes, developed by Philosophy. Although there should be a shout out to Leibniz here.

The reality is that the only formal logic today which is proper logic is that from Aristotle up to the Scholastic.
Unless anyone could prove otherwise.
EB

[Arising_uk]

They tried to develop a mathematical method of formal logic and failed. All they could produce was the aptly named "1st order logic" as it is at best a 1st order approximation. In so doing, they behaved essentially as mathematicians, and not as philosophers or logicians. ...

Well I can understand that a calculus for logic could be considered as mathematical but they developed it for Aristotle's informal logic and produced Formal or Symbolic Logic and you can understand why, as the natural philosophers had well and truly put the kibosh on the Aristotelian idea that you could just think about the world and come to the correct conclusions about it. From what I gather from Logik much more has been produced than just '1st order' logic since that time.

Well, as far as I know, pretty much all of the current philosophy of logic defers to mathematical logic. The only actual logic left is the study of Aristotle, the Stoics and Scholastics. ...

I guess that depends upon what you want to do with Logic within Philosophy.

The reality is that the only formal logic today which is proper logic is that from Aristotle up to the Scholastic.
Unless anyone could prove otherwise.
EB

You'd have to say what you think 'proper' logic involves?

[Arising_uk]

The problem with your definition of philosophy is that it comes THAT close to defining itself, but not close enough.
How do you determine if you have clarified your thoughts/ideas sufficiently? ...

Me personally? I clarify my objective with a linguistic model, then I make sure my representations are all congruent and my feelings are as well, I future run them using various psychological tools and then I use a TOTE system to reach the objective. You?

This is the "criterion" problem in epistemology. ...

A problem since the Romans if I recall. But I thought you didn't listen to Philosophy?

With Lambda calculus - you don't have to. Because Lambda calculus produces behaviouristic models. ...

I am interested in what you say as I come from a non-mathematical background and my Logic pretty much stopped at Modal and First Order. So how would you use this calculus to define Philosophy?

You don't ask whether your idea is clearly explained. You ask whether your model behaves as expected. ...

How do you get this model in the first place?

You are falling for the trap of linguistics again. Is there a logic that is NOT a metaphysic? If you can't classify some logics as NOT being metaphysics then you've invented a truism. ...

I thought I was talking about a model for Physics?

For the purpose of debate ALL logic is metaphysics. ...

So how do you choose your Logic?

First order logic is metaphysics.
High order logic is metaphysics also.

The difference is that one is like LEGO for 3-5 year olds, and the other is like a lego for grown ups.

Flexibility, scale and complexity are the distinguishing marks of Lambda calculus. You can invent your own LEGO bricks.

I look forward to learning how it is applicable to living and thought.