All; therefore some?

[Jokodo]

It would be, yes. But that would require a non- classical trivalent logic and the additional assumption that the existential presupposition is actually part of the semantics of "all" and not a pragmatic import, something you haven't shown, and won't be able to unless you get a good grasp of the difference between semantics and pragmatics.

Ad hominem.

Huh? I just said that, in order to make the argument that a specific English word has a specific core meaning (and not just tends to carry certain presuppositions in most contexts where it is typically uttered), you need to understand that speaker meaning is a conglomerate of semantics and pragmatics.

I could add that the way you jump from the observation that "All angels are wings" isn't usually claimed by someone who doesn't believe in angels to the conclusion that the existential import is part of the literal meaning of "all" indicates that you lack that understanding, but I haven't actually said that (up to now).

Looks more like a case if you misunderstanding the scope and purpose of logic from where I am standing.

I don't care where you are standing. I asked a question, you provided an opinion you can't support from empirical evidence.

Fine with me.
EB

I didn't provide an opinion, I provided an explanation of what the quantifier ALL in formal logic means, by convention. Maybe you misremember what question you asked? It was a question about logic, not a question about English. I know this because of what you wrote in the very first sentence of your OP: "Ah, here is a very interesting piece of logic." The word "English", on the other hand, doesn't occur in your OP at all. I also know this because you chose to post in the "Logic and Epistemology" subforum of the Philosophy section of this forum. If this were a data question about English native speakers intuition on the meaning of a particular word of the English language, I would expect it in Social Science, or possibly Natural Science, wherever you think linguistics best fits. And I might have answered differently, or not at all given that I'm not a native speaker.

 

[Jokodo]

In classical mathematical logic, it does.

I didn't ask any question about mathematical logic.

You certainly didn't ask any question about the English language. The word "logic" is right there in the first sentence of your OP, the word "English" is nowhere to be seen.

You haven't even tried to show that they are different.

Whoa!!! It is for me to disprove that God exists?

And I thought I was asking a question. Now I have to provide the answer, too.
EB

So when you said that "It is just a case of mathematicians being unable to produce a correct model of the deductive logic of human beings", you weren't making a claim?

 

[Jokodo]

You think the lecturer would have to conclude turned off cell-phones don't exist?!

As per the scenario, they indeed do not exist within the discourse domain, which is the lecture room. That happens in nearly all real-life contexts of universal quantification: The claim is meant and understood to hold of a specific context, not the entire universe. If we slightly change the scenario such that 5 of the students in this particular course at MIT do have a phone on them and she starts the class when all five have turned it off, you wouldn't accuse the lecturer of lying because someone in France and someone in California have their phones on? I mean, she did say she won't start until all phones are turned off. Without restricting the domain of the quantifier to the phones in the room, the condition hasn't been met.

You think the police would have to conclude foreign workers don't exist?!

Again, within the relevant domain, that is at this particular company, they don't exist.

Even intuitively, a situation where there are no phones qualifies as one where all phones are turned off,

Intuitively, certainly not.

Are you going to accuse the lecturer of lying when she starts the class in a room with no phones, because she earlier said she won't start until all phones are turned off? If so, I think it's fair to say it's your intuition that's broken, not mathematical logic.

or one where there are no foreign workers as one where they've all successfully produced their work permits.

Intuitively, certainly not.

Imagine the following dialogue:
Chief inspector: Have you checked all foreign workers' work permits.
Second inspector, version 1: Yes (well more specifically, there were no foreign workers).
Second inspector, version 2: No (but only because there were no foreign workers).
Second inspector, version 3: You question is meaningless (because there are no foreign workers).

I'm pretty sure that version 3 will get the second inspector fired for being a pain in the ass. Version 2 works with the paranthesised explanation, but without it, version 1 seems most felicitious, whether it's technically correct or not.

The fact that the existential presupposition as an apparent component if the meaning of "all" can be so easily ignored given proper context is actually a telltale sign of its pragmatic nature, making your job of demonstrating that it is semantic rather unfeasible.

I don't have a job here. I asked a question, you provided an opinion that you cannot support from empirical evidence.
EB

It looks like you're confusing at least three different things here: The logical quantifier ALL, the literal meaning of the English word "all", and the speaker intent we attribute when hearing a sentence containing the latter. There's a reason why formal logic, natural language semantics, and natural language pragmatics are three different fields of study: Because they analyse three different domains of phenomena.

Your question was, explicitly so, about logic. I provided an answer to that question, and now you try to make it look like you were asking about something else. It doesn't actually matter to your original question whether an existential presupposition is part of the lexical meaning of the English word "all". What if it's true that English "all" in a sentence like "all X P" means something that can be paraphrased as "there is at least one X, and there is no X for which P doesn't hold"? It would still be preferable to decompose this conjunctive meaning into two atomic components for the purposes of formal logic to arrive at an overall more elegant system. ETA: And it would be from the existential part, not from the universal part, that the conclusions in your examples follow.

Your notion that logical operators should have a meaning exactly matching that of the English word they most resemble is not founded on any objective argument, and is all the more hilarious given that you don't seem to be equipped to objectively analyse what those English words even mean (in the sense of their core semantics, abstracting away from the pragmatics of a particular context). When a competent speaker of any human language hears or reads another make a statement, a lot of things happen simultaneously - not just anylising the literal meaning of what has been said, but making a host of assumptions why they would say that, and assumptions about other believes (not expressed by what they said) that would make saying what they did say a meaningful contribution to an exchange of ideas.

It may be the case that "all" has an existential presupposition as part of its meaning. Or it may be the case that it doesn't, but when we hear someone say "all angels have wings" we automatically assume that at least they believe angels exist - because we give them the benefit of the doubt that they are at least trying to tell us something they believe to be true and which we didn't know, and a vacuously true statement doesn't qualify. Either way it is irrelevant to the meaning of the logical operator ALL.

 

[Speakpigeon]

Huh?

"unless you get a good grasp of the difference between semantics and pragmatics"

Here you are assuming I don't have a good grasp of the difference between semantics and pragmatics.

Sorry, you don't know that, so it is an ad hominem.

I just said that, in order to make the argument that a specific English word has a specific core meaning (and not just tends to carry certain presuppositions in most contexts where it is typically uttered),

I am not making that argument.

I take deductive logic to be more fundamental than language, but syntax and vocabulary essentally follow from the constraints imposed by the medium of verbal and written expression, including, although I'm not supposed to understand that, pragmatic constraints.

You only need to look at the definition of "all" and "some" to see the effect of these constraints. Logic isn't in the words.

Also, words don't have meaning, not even a "core meaning". Where did you learn that one?!

Words may have a definition. They don't have any meaning

you need to understand that speaker meaning is a conglomerate of semantics and pragmatics.

You probably want to say rather that the semantics of the message is a conglomerate of (speaker) meaning and pragmatics (of the communication act).

I could add that the way you jump from the observation that "All angels are wings" isn't usually claimed by someone who doesn't believe in angels to the conclusion that the existential import is part of the literal meaning of "all" indicates that you lack that understanding, but I haven't actually said that (up to now).

You are hearing voices.

I never claimed that "the existential import is part of the literal meaning of 'all'".

Then again, the facts of language are part of the little empirical evidence we have about logic.

I didn't provide an opinion, I provided an explanation of what the quantifier ALL in formal logic means, by convention. Maybe you misremember what question you asked? It was a question about logic, not a question about English. I know this because of what you wrote in the very first sentence of your OP: "Ah, here is a very interesting piece of logic." The word "English", on the other hand, doesn't occur in your OP at all. I also know this because you chose to post in the "Logic and Epistemology" subforum of the Philosophy section of this forum. If this were a data question about English native speakers intuition on the meaning of a particular word of the English language, I would expect it in Social Science, or possibly Natural Science, wherever you think linguistics best fits. And I might have answered differently, or not at all given that I'm not a native speaker.

And what does this has anything to do with mathematical logic?!

Your opinion, since you need some spelling out, is to think mathematical logic is the same as logic. My thread, as you've noticed, is very explicitly about logic. Thus, it is very explicitly not about mathematical logic and not about "formal logic".

If you think it's all the same thing, you would have to justify your opinion and you are clearly unable to do that.
EB

 

[Speakpigeon]

You certainly didn't ask any question about the English language. The word "logic" is right there in the first sentence of your OP, the word "English" is nowhere to be seen.

Here is some reading for you. It seems you need to learn first how the word logic is defined...

logic
n.
1. The study of principles of reasoning, especially of the structure of propositions as distinguished from their content, and of method and validity in deductive reasoning.
2.

a. A system of reasoning: Aristotle's logic.
b. A mode of reasoning: By that logic, we should sell the company tomorrow.
c. The formal, guiding principles of a discipline, school, or science.​

3. Valid reasoning: Your paper lacks the logic to prove your thesis.
4. The relationship between elements and between an element and the whole in a set of objects, individuals, principles, or events: There's a certain logic to the motion of rush-hour traffic.
5. Computers

a. The nonarithmetic operations performed by a computer, such as sorting, comparing, and matching, that involve yes-no decisions.
b. Computer circuitry.
c. Graphic representation of computer circuitry.​

[Middle English, from Old French logique, from Latin logica, from Greek logikē (tekhnē), (art) of reasoning, logic, feminine of logikos, of reasoning, from logos, reason; see leg- in the Appendix of Indo-European roots.]

So when you said that "It is just a case of mathematicians being unable to produce a correct model of the deductive logic of human beings", you weren't making a claim?

Sure, based on my observation of what you said.
EB

 

[Jokodo]

"unless you get a good grasp of the difference between semantics and pragmatics"

Here you are assuming I don't have a good grasp of the difference between semantics and pragmatics.

Sorry, you don't know that, so it is an ad hominem.

You haven't shown any indication that you do.

I am not making that argument.

I take deductive logic to be more fundamental than language, but syntax and vocabulary essentally follow from the constraints imposed by the medium of verbal and written expression, including, although I'm not supposed to understand that, pragmatic constraints.

You only need to look at the definition of "all" and "some" to see the effect of these constraints. Logic isn't in the words.

Which definition? The definition someone writing a dictionary managed to formulate because he would have hated to look at a blank page? As a linguist, I prefer to empirically study the actual interpretations of sentences containing those words to derive at a objectively motivated model of what they might mean - when that's the question. When the question is however about logic, than only the definitions of the universal and existential operators as defined within a particular logic (unless stated otherwise: standard predicate logic) matters.

Also, words don't have meaning, not even a "core meaning". Where did you learn that one?!

Words may have a definition. They don't have any meaning

you need to understand that speaker meaning is a conglomerate of semantics and pragmatics.

You probably want to say rather that the semantics of the message is a conglomerate of (speaker) meaning and pragmatics (of the communication act).

I want to say exactly what I said.

I could add that the way you jump from the observation that "All angels are wings" isn't usually claimed by someone who doesn't believe in angels to the conclusion that the existential import is part of the literal meaning of "all" indicates that you lack that understanding, but I haven't actually said that (up to now).

You are hearing voices.

I never claimed that "the existential import is part of the literal meaning of 'all'".

You used the fact that people commonly understand examples like the one in your OP to have existential import (necessary to make the conclusions follow) as an argument that logicians are wrong in how they define the meaning of the operator ALL. This argument makes sense under two premises: Logical operators must mirror natural language quantifiers, and the natural language quantifier "all" has existential import as part of its meaning. You haven't justified either premise.

Then again, the facts of language are part of the little empirical evidence we have about logic.

I didn't provide an opinion, I provided an explanation of what the quantifier ALL in formal logic means, by convention. Maybe you misremember what question you asked? It was a question about logic, not a question about English. I know this because of what you wrote in the very first sentence of your OP: "Ah, here is a very interesting piece of logic." The word "English", on the other hand, doesn't occur in your OP at all. I also know this because you chose to post in the "Logic and Epistemology" subforum of the Philosophy section of this forum. If this were a data question about English native speakers intuition on the meaning of a particular word of the English language, I would expect it in Social Science, or possibly Natural Science, wherever you think linguistics best fits. And I might have answered differently, or not at all given that I'm not a native speaker.

And what does this has anything to do with mathematical logic?!

Your opinion, since you need some spelling out, is to think mathematical logic is the same as logic. My thread, as you've noticed, is very explicitly about logic. Thus, it is very explicitly not about mathematical logic and not about "formal logic".

If you think it's all the same thing, you would have to justify your opinion and you are clearly unable to do that.
EB

Since you were using logic in the singular, without specifying which logic, the only logical conclusion I could draw was that you are talking about classical predicate logic, which, like it or not, happens to be kind of the default logic these days. If you aren't, it's up to you to clarify.

 

[Jokodo]

Here is some reading for you. It seems you need to learn first how the word logic is defined...

Nowhere in there does it say that logic is the study of what particular English words are used to express which concepts and relations.

So when you said that "It is just a case of mathematicians being unable to produce a correct model of the deductive logic of human beings", you weren't making a claim?

Sure, based on my observation of what you said.
EB

So you are making a claim you cannot justify? Something I haven't done in this thread, and yet you accuse me?

 

[Jokodo]

It's clear to everyone that you are on a crusade against what you call "mathematical logic" (and which other people simply call logic).

It's also clear to everyone except yourself that you have - yet again - failed to demonstrate that it is useless, despite your childish insistence to the contrary.

 

[Speakpigeon]

It's clear to everyone that you are on a crusade against what you call "mathematical logic" (and which other people simply call logic).

It's also clear to everyone except yourself that you have - yet again - failed to demonstrate that it is useless, despite your childish insistence to the contrary.

Again, I didn't ask for mathematical logic. Logic exists since Aristotle, 2,500 years ago, and indeed well before that in the minds of all human beings.

Anyway, again, thank you for your patience, I'll try to reply to your posts later.
EB

 

[Speakpigeon]

Either way it is irrelevant to the meaning of the logical operator ALL.

In mathematical logic, sure.

Whether it's relevant in real life, this was what I was trying to elucidate until you decided to start a lecture on mathematical logic.

So, well done, but as I said, I'm not interested.

I'm interested in logic.
EB

 

[Jokodo]

It's clear to everyone that you are on a crusade against what you call "mathematical logic" (and which other people simply call logic).

It's also clear to everyone except yourself that you have - yet again - failed to demonstrate that it is useless, despite your childish insistence to the contrary.

Again, I didn't ask for mathematical logic. Logic exists since Aristotle, 2,500 years ago, and indeed well before that in the minds of all human beings.

Anyway, again, thank you for your patience, I'll try to reply to your posts later.
EB

Writing exists since the Sumerians, but you wouldn't expect me to answer a question "how do you write X" with a cuneiform character.

Or would you?

 

[fromderinside]

I'm interested in logic.
EB

Would you say that your view of of what is logic arises from  rationalism and tradition?

 

[Jokodo]

Either way it is irrelevant to the meaning of the logical operator ALL.

In mathematical logic, sure.

Whether it's relevant in real life, this was what I was trying to elucidate until you decided to start a lecture on mathematical logic.

So, well done, but as I said, I'm not interested.

I'm interested in logic.
EB

It is irrelevant in any properly defined system if logic.

What exactly the English word "all" means in some, all or most contexts, to some, all or most speakers is an interesting question - but it's a linguistic question, not a logics question. I don't say this in a disparaging way - I have a linguistics degree. It's just not relevant to the question you yourself have staked out.

 

[fast]

All angels have wings;
Therefore, some angel has wings.

Few thoughts:

1) There seems to be a silent (hidden) premise. If I unmasked it, the argument would look like this:

P1. If all angels have wings, then some angels have wings
P2. All angels have wings.
Therefore C., Some angels have wings.

2) quantifiers do not work the same in all situations. Sometimes, they are appropriately interpreted differently.

There were 40 cookies, and I ate 40 cookies, so I ate all the cookies and no cookie went uneaten by me. I ate ‘at least’ some of the cookies, but did I eat some of the cookies? How is it exactly that some angels have wings if in fact all do? At least some, yes, but some?

3) the argument I gave is valid, but it’s independent of any truth of the premises. Target the conclusion and glance around to see if there’s enough in what’s given to arrive at the conclusion.

 

[fromderinside]

I'm interested in logic.
EB

Would you say that your view of of what is logic arises from  rationalism and tradition?

I asked because you wrote

Again, I didn't ask for mathematical logic. Logic exists since Aristotle, 2,500 years ago, and indeed well before that in the minds of all human beings.

 

[Jokodo]

All angels have wings;
Therefore, some angel has wings.

Few thoughts:

1) There seems to be a silent (hidden) premise. If I unmasked it, the argument would look like this:

P1. If all angels have wings, then some angels have wings
P2. All angels have wings.
Therefore C., Some angels have wings.

2) quantifiers do not work the same in all situations. Sometimes, they are appropriately interpreted differently.

There were 40 cookies, and I ate 40 cookies, so I ate all the cookies and no cookie went uneaten by me. I ate ‘at least’ some of the cookies, but did I eat some of the cookies? How is it exactly that some angels have wings if in fact all do? At least some, yes, but some?

3) the argument I gave is valid, but it’s independent of any truth of the premises. Target the conclusion and glance around to see if there’s enough in what’s given to arrive at the conclusion.

That's quite clearly pragmatics. We don't expect speakers to make a weaker claim when they could have made a stronger one, so the weaker one seems infelicitous unless the stronger is false. I have a brother and two sisters. If I say "I have a brother" in answer to the question "do you have siblings?", people will judge me as an uncooperative interlocutor - despite having made a true statement. That it is indeed true can be verified by the fact that, were the question "do you have a brother", the expected answer would be "yes".

The same happens with "some" - we assume the speakers knows whether "all angels" is also true, and we expect them to give us the most informative utterance that's compatible with their knowledge. The fact that they didn't say "all angels have wings" lets us conclude that it's incompatible with their beliefs - but nowhere did they tell us that some other angels don't have wings.

It can be shown that the inference "and some don't/aren't" goes away in contexts where the speaker isn't expected to know, or when quantifying over situations, in some of which "all" doesn't hold while in others it does. For example "some of my great-great-grandfathers where farmers" seems perfectly acceptable when I only know what 4 of my 8 great-great-grandfathers did for a living, all 4 of which were farmers, and even suspect that the rest might have been farmers too. And the statement "if some of your family members are foreign citizens, you'll know what a pain in the ass the immigration office can be" obviously includes the case where all one's family members are foreign citizens.

But thanks for demonstrating that building a logic on raw intuitions in a particular context is doomed to fail, and thus any logic worthy of the name has to make some (sometimes arbitrary) decisions about defining the semantics of its operators.

 

[Speakpigeon]

I'm interested in logic.
EB

Would you say that your view of of what is logic arises from  rationalism and tradition?

Not one bit.

My take is to apply the scientific method, which should have become obvious to all here given my many threads on the subject.

For empirical evidence, I look at Aristotle, the Stoics and the Scholastic, as well as posters who are not biased by a schooling in mathematical logic, which is obviously wrong.

I also take into account my own logical intuition as perception, in the same way that a scientist has to trust his perception.

You've long been barking up the wrong tree with your "Rationalism". I abide not by Rationalism but by rationality, which I sensibly define as "facts plus logic", and I don't think anyone could fault me for that.
EB

 

[Speakpigeon]

All angels have wings;
Therefore, some angel has wings.

Few thoughts:

1) There seems to be a silent (hidden) premise. If I unmasked it, the argument would look like this:

P1. If all angels have wings, then some angels have wings
P2. All angels have wings.
Therefore C., Some angels have wings.

2) quantifiers do not work the same in all situations. Sometimes, they are appropriately interpreted differently.

There were 40 cookies, and I ate 40 cookies, so I ate all the cookies and no cookie went uneaten by me. I ate ‘at least’ some of the cookies, but did I eat some of the cookies? How is it exactly that some angels have wings if in fact all do? At least some, yes, but some?

3) the argument I gave is valid, but it’s independent of any truth of the premises. Target the conclusion and glance around to see if there’s enough in what’s given to arrive at the conclusion.

As Jokodo said, pragmatics fully explains your observations. Logic is much more simple than that. Simple question, simple answer.
EB

 

[Speakpigeon]

I asked because you wrote

Again, I didn't ask for mathematical logic. Logic exists since Aristotle, 2,500 years ago, and indeed well before that in the minds of all human beings.

And?
______________

So, which of my arguments are valid, and which are not?
EB

 

[Jokodo]

I'm interested in logic.
EB

Would you say that your view of of what is logic arises from  rationalism and tradition?

Not one bit.

My take is to apply the scientific method, which should have become obvious to all here given my many threads on the subject.

For empirical evidence, I look at Aristotle, the Stoics and the Scholastic,

"Aristotle, the Stoics and the Scholastics" and "empirical evidence" in the same sentence.

as well as posters who are not biased by a schooling in mathematical logic, which is obviously wrong.

It's not "obviously" anything until you've provided an argument that it is. "I don't like it" is not an argument.