if you imagine Pegasus, whatever you imagine exists as something you imagine.

No one said what you imagine has to have wings. — Terrapin Station

This was all you had to say before so I thought it was very obvious what I was responding to (the rest was more a screed than anything related to this topic).

The proposition "Pegasus is a flying horse" and "Pegasus is an imaginary flying horse" are not identical. If one is not careful (i.e. in how they regard existential quantification), the former implies existence while the latter does not ("imaginary" is understood usually as entailing non existence).

What you're missing is that imagining that Pegasus has wings is not the same as Pegasus having wings. What is true of a thing that is real is not the same as what's true of a thing that is imaginary. If Pegasus were real the property "is imaginary" would not apply, while that property would apply to what I'm imagining. In other words, what one imagines can't have the same properties as a physical instantiation of what I'm imagining.

People can debate that but it ends up coming across as Meinongianism at a certain point. And that's not totally indefensible (though it may come at some steep costs), but most don't want to be committed to that view.

Perhaps if you read you'd notice I responded to the things you said, quoting or not. It's not hard to read.

Which I already did in the very post you quoted the beginning of.

You're not making any sense and using snark to bolster it is more funny than compelling. If I imagine Pegasus, that doesn't make Pegasus exist at all. An imagination of a thing does not give the thing any more ontology than it did before, it's just a representation of something that might or might not exist. By this standard a statue of Pegasus would make Pegasus more real.

After all, it's just as true to say "Pegasus does not exist" before I imagine it as it is during the process of imagination. Would you honestly go up to someone and say, "Well of course Santa Claus did not exist but now that I've brought him to your mind he exists in your imagination"? You might as well have said he doesn't exist at all, imagination or not.

The process of imagining existing is not equivalent to the content of the imagination existing. Pegasus is not conceived of as an imaginary horse that flies. Pegasus is conceived as a horse that flies, and it may be that we imagine it. My imagination of Pegasus does not have wings, it doesn't exist in the first place. The content of the imagination, if real, would have wings. But since it's a fiction, it doesn't exist at all.

It's impressive that I'd be stuck in that mindset despite being neither an academic philosopher nor have I even read in this topic.

Again, consider the obvious objections to what you're putting forward. Pegasus is not defined as a fictional being, though we know it to be so because it does not exist. And yet under your view Pegasus both has to exist as a fiction (non-existent) and it has to have the properties of existing things that are part of the concept of Pegasus: having wings, immortal, created by Zeus, etc. This surely isn't true about the fiction of Pegasus (fictions cannot be created by non-existent beings, nor have wings, etc.), but it's part of the proposed attributes of the entity we know to be fictional.

"Pegasus was created by Zeus" being true is not equivalent to "The fiction known as Pegasus was created by Zeus" being true, but the little you've said would seem to suggest they ought to be equivalent. The former implies that Pegasus exists while the latter does not. It's like your flipping contexts or something.

That's probably fine. How to resolve this logically isn't clear. Maybe it was in another thread, but I've mentioned before that some have suggested adding an quantifier that is specifically for quantifying over fictional things. Don't know if that solution or any other works, I've not looked into this all that much.

I know you mentioned it but the post doesn't say anything about why one should adopt psychologism especially given everything that mounted against it at the end of the 19th century with regards to logic and mathematical truths. (Not sure if you meant something different by psychologism so I'm guessing).

Yeah, obviously what people tend to have in mind with something like "God doesn't exist" is that he doesn't exist as anything other than a fiction. Folks aren't saying the fiction doesn't exist as a fiction. — Terrapin Station

Eh, this seems like a dubious claim about what people 'tend to have in mind'. A fiction is, colloquially, understood as something that doesn't exist. And as I don't happen to believe in God, I definitely don't think God exists and does so as a fiction. I would say God does not exist because the idea of God has no referent, it is not among the set of existing things. "Existing as a fiction" sounds like non-existing existent to my ears. There's certainly a collection of proposed attributes and actions written and believed to have been done by some being called God, but I wouldn't attributes any kind of existing to that hypothetical person.

Because "imagined" is usually understood as implying non-existence. So that statement would be rendered as "Why should we say that non-existent things do not exist?". The answer seems obvious enough.

You don't want to be in the situation where you agree to existentially quantify over something and say true things about it, but you maintain that it does not exist (e.g. There exists some x such that x is Sherlock Holmes and Holmes is etc etc.). I mean what you're saying sounds like Meinongianism and I'm assuming you don't endorse that.

All we're saying is that the proposition "Sherlock Homes lived at 221B Baker Street" corresponds to what Doyle wrote, for example (because that's what he imagined/what he chose to construct), for example. Why in the world would there be limitations like that on what something can correspond to? — Terrapin Station

Well surely a true statement is not directly made true by a non-existent thing? I'm fine making a distinction between what makes different kinds of propositions true or not (those making reference to imagined things vs real things) but speaking of imagined things existing seems like a contradiction. Meinongianism isn't entirely off the table nowadays (oddly enough) but it's a bitter pill to swallow...

That's almost word for word what I was going to come here to say. :)

I wasn't saying "truth" is only correctly captured by correspondence theory, just that since that theory of truth is a fairly normal way people understand truth, it's a tricky issue holding these without thinking it through carefully.

That's just pushing the issue off to say it's truths about imagined things (obviously this is right). Truths about imagined things are truths about things that don't exist, so it doesn't seem to do anything to progress the seeming conflict between the intuitive correspondence theory of truth and there being truth propositions regarding non-existent or fictional entities. Surely it sounds strange that "X is true because it corresponds to an imagined Y/how Y imagined X?

Isn't the whole issue that one can say true things about objects that don't exist? If I say "Sherlock Holmes is a clever detective" few will say it's simply a false statement. Given it's truth, on it's face, contradicts that correspondence theory of truth (which is seemingly a fairly straightforward way to understand truth) the issue doesn't seem so easily cleared up with derision about philosophers being silly or what have you.

That's not comparable. Separate pillows are not the same object nor are they logical negations of each other. Beliefs of a single person at a specific point of time are part of the same set of beliefs (not the same belief, that's not what I said) and that set can contain inconsistencies.

I am linking tangible, observable phenomena with existence. We are able to observe and interact with innumerable things and do so on a daily basis. That is undeniable.

You seem uncertain about existence. You seem doubtful that things exist — daniel j lavender

No. I made no doubts that things exist. My point, which you didn't even attempt to address, was that you haven't given anything like a useful definition of existence. No one is doubting that there are things which exist, what I'm doubting is how you're going about defining that term.

Declaring "no time", "no matter", "no space", "no motion", etc., is essentially declaring nothing, or nonexistence. What else would such be? Non-existing existence? Your premise simply does not make sense. You are declaring nothing while declaring it is not nothing. You are declaring a state that is not a state. Then declaring something just came about. Nonsense all the way around. — daniel j lavender

It's isn't anything. What I'm saying is that your intimation that people who suggest a first moment of existence are no suggesting there was a state of nothingness from which the first moment popped into being from. Its a contradiction, you know that. You're essentially begging the question in favor of your own position, namely that there was always some kind of state which is the very thing you're supposed to be arguing for. Even here you're attempting this despite thrice telling you that's not what is meant. It's disingenuous. It's not the suggestion that there was a state of non existence, but that there was no state at all because there wasn't anything.

As stated above, the philosophy advanced here is not limited to the term "universe". This philosophy concerns the term "existence". For a reason. — daniel j lavender

Call it whatever you want. We understand the existing world, we do not have anything substantial to go on for ascertaining why anything exists. You tried making comparisons to thinking things popping into existence being absurd and suggesting it violates conservation of energy. These are facts about things within the existing world, not explanations for why reality exists.

Poof! Existence! Is too magical to be taken seriously. Furthermore, you have conveniently failed to adequately refute any of my arguments concerning energy, its dynamics and how they relate to an eternal, infinite existence. — daniel j lavender

I can play this game too. "Oh, you believe in an infinite past? No explanation for the universe at all! Poof! Infinite regress of past explanations, magic!"

Those are not arguments for an infinite past. This is exactly what I said you were doing. Those are descriptions of the universe, an existing thing. They do not provide an argument for why the universe exists at all.

Existence exists" simply means "existence is". "Nonexistence does not exist" simply means "nonexistence is not". — daniel j lavender

That doesn't explain anything. Is *what*? You're not linking anything to existence here, you're just saying there things which exist and things which don't. You haven't explained what those terms, what those predicates, actually mean. You're simply restating what they entail.

I'm asserting that existence concerns that which can be observed or interacted with in some way, but doesn't necessarily need to be. — daniel j lavender

But there are things which could not be observed in any way. Unobservables are the obvious examples. We don't interact with them, we postulate them to explain certain data in our best theories.

If something, such as a "first moment", was not preceded by anything then that implies nothing preceded it.

Nothing/Nonexistence couldn't possibly precede anything because it does not exist. In other words, it wouldn't really "be before". Your suggestion of a "no before" is indeed alluding to a "nothing before". That's nonexistence. — daniel j lavender

You are doing the exact nonsensical thing I mentioned. People who say there is a first moment of time are not saying there was a state before the first moment and that state was nothing. That's the idiotic assessment of their view. There is no *before* the first moment any more than there is a north of the North Pole. It's just a category mistake, there could not be time before time, "before" is a temporal concept that can only be applied to temporal sequences. No one is suggesting there is a "nothing before" the first moment of time because "nothing" is not a state on pain of contradiction, for a state is itself something. It's saying there wasn't anything because there couldn't be.

You are, hilariously enough, treating nothingness as if it were a state of affairs which is a clear contradiction.

Again, how does stuff just "pop into being"? It's akin to saying energy simply comes about. We know that's nonsense. Energy must be derived from something, it must come from something. Energy is neither created nor destroyed, it is only converted into different forms. It is the same with existence. — daniel j lavender

How does stuff persist forever when an infinite past would have long ago reduced the universe to a wasteland? Anyone can play these hypotheticals when we're jacking off about a matter that is poorly understood. You're extrapolating natural laws to explain the existence of the subject described by the natural laws. Not sure that's going to make sense.

Where did the material for the physical universe/existence come from? What catalyzed such an event? How does such an event occur without any previous phenomena? You must explain this. — daniel j lavender

Begging the question. Asking "what material" and "where did it come from" are just importing the assumption of an infinite past into the framing of your question. Again, we know how things work once we have a universe, you cannot extrapolate that back as an explanation of why anything exists in the first place.

Actually the implication is closer to "that which exists can be observed because it exists, and that which does not exist cannot be observed because it does not exist".

That which does not exist cannot be observed (or interacted with). That which does exist can be. — daniel j lavender

No no, you were giving a definition of existence and then the implications you drew from it seemed incoherent. You quoted a definition saying existence regards things which can be observed and then you said "Existence exists", whatever that means (sounds trivial) and I found any subsequent points to be gibberish.

Think about it, if "that which exists can be observed because it exists" is elucidating anything, it's that things which exist are observable (and indeed, you outright say this in the above quote). But this a borderline untenable position that I hopefully don't need to explain much (just consider so-called "unobservables" in scientific models, or even just extremely distant objects that no observer will ever see).

As stated above, my points are fairly straightforward. I am asserting that existence is infinite in extent, and eternal in duration. I am also asserting that we are parts of existence. — daniel j lavender

Oh I know you're saying this, but you aren't actually arguing for it. Even in your OP you don't really provide a logical throughline for thinking existence is infinite, you just misrepresent the idea of a finite past, as I'll show again in a moment.

The idea of a "beginning of existence", or a "first moment of time" suggests that existence just began. How would you explain that? It is essentially a something-from-nothing premise. ("No before" essentially implies nothing.)

How does something, how does time, just come about? This must be explained.

How does existence "just begin"? — daniel j lavender

Explain what? If there was a first moment of time then t1 is the first state to exist and was not preceded by anything on pain of contradiction.

I don't really see how an eternal view of things is somehow more parsimonious. In actual fact, it's infinitely more complicated because it posits an infinite chain of facts to explain one datum (that things exist) and so would in normal circumstances not have the high ground in simplicity. I'm not sure how it's in need of explanation anymore than an infinite past. In fact, the obvious contention against an infinite past is exactly why it is infinite. There's no logical necessity in the past being either finite or infinite specifically. The how question here is framed as if an infinite past is actually understood in full and thus need not explain itself.


But all that aside, as in my earlier objection, the things your deriving from your notion of existence are practically incoherent and poorly phrased (please never again say "Existence exists", it sounds like objectivist nonsense...).

OP is nothing but arguments by what look like dictionary definitions as well as repeated affirmations of things not argued for and by using sloppy language. Prime examples being:

Existence exists and nonexistence does not exist.

Existence exists because nonexistence does not exist.

Existence is everywhere. Nothing is nowhere. Nothing does not exist, it is no thing. Every thing is something, including space.

Existence did not begin as a "beginning of existence" would imply a previous state of nonexistence, and nonexistence does not and did not exist. For example, the Big Bang required some sort of catalyst or environment to facilitate it. — daniel j lavender

I mean if you try using the definition of existence given from the seeming dictionary definition OP gave, these assertions are rendered as "That which is observed is observed because that which is not observed is not observed". What this is supposed to communicate about the meaning and implications of existence, I do not know. It's not giving me a real understanfing of what you think existence is. It's like using the word "true" in your definition of truth.

Further, existence having a beginning does not imply there was a state of so called non-existence beforehand. That's a logical doozy because it contradicts itself, but not in the way OP intended. It can easily mean there was a first moment of time. There's no "before" a first moment because "before" is a temporal concept, and clearly someone positing a first moment of existence is not positing a time before time. That's just dumb.

Existence is infinite, however, our limited perspective creates an illusion of limitation — daniel j lavender

You do not give an arguments for this at all, this reads almost like an ideological affirmation. And I'm someone who thinks some aspects of reality may well be infinite in a sense. But I've no clue why you think anything is infinite, you're just telling us it is.

OMG whyyyyy

I'd say observing a thing reliably and consistently being some way if perfectly fine way of establishing something to be true generally. That's not science, otherwise science would be too broad a category and no one would regard it so highly. I see, feel and hear this phone in my hand, so I'd say that's about as good evidence as required to reasonably assert that "My phone exists" is true.

Then why not make this general consensus business the method of establishing truth? Because either way your initial postulate is false on pain of vicious circularity. It fails its own dictum unless it relies on itself, which isn't gonna be very helpful.

If we assume that accessibility relations are the same across possible worlds, then that assumes a form of scientific essentialism. This is because rigidity and necessary conditions are guaranteed through adhering to properties that are immutable, such as the laws of physics and nature. — Wallows

But accessibility relations are determined by the properties of the modal logic in use (basically which worlds can quantify over other worlds given certain properties like transitivity or Euclideanness), they aren't properties of the possible worlds themselves, right? I'm not sure if this is essentialism.

Go back and read what I wrote. I never claimed that Nazis came to power ONLY by limiting free speech. They used violence against anyone who spoke negatively about the party. THAT is limiting free speech — Harry Hindu

What I thought you were suggesting was that this was what was done after they took power. That was my mistake.

That isn't what I was saying. I said the best way to combat Nazism is by letting them express their ideas and then expose their ideas to criticism. Not only that, but it's always nice to be able to know what your neighbors think and where they stand. — Harry Hindu

I think this is the main thing I found startling, and I'm not even advocating for further free speech restrictions on this basis. This makes a number of huge assumptions based on idealized notions of rationality. You seem to think that Nazis (or fascists and the extreme-right more generally) honestly present and articulate their views and people weigh those in a fairly unbiased manner. That's surely not true, just take even lesser right wingers like the standard GOP talking points on any number of issues. Illegal immigration is framed in terms of diseased immoral peasants and/or an invasion by a foreign army storming over the border to commit rape, theft, murder, drug sales and steal jobs, all supposedly more than the citizens of the country. And what does this do to so-called the typical conservative and their views (or even so-called independents, I suspect)? Do they think these claims through? Or do they instead swallow them more or less whole because they already agree with the conclusion that they don't want any more illegal immigrants? They've already started down the path to fascism, and even falling short of that they're made into a useful bloc to prop up those with extreme RW ideologies, arguments be damned. Arguments against them are immediately seen a the political machinations of liberals who hate America and want white people to be a minority.

This holds for any number of issues, people of every ideology don't really listen to the other side (not that this is always unwarranted). People have their views and generally hold to them pretty strongly, with change coming often for personal reasons, not rational arguments in a public forum or with the neighbors. I mean I ask you, how often have you changed a significant political view based just on an argument someone gave you? Or how often have you seen people you know change in this way? Maybe one thinks themself out of some things but I suspect that's because we value our own discovered insights over the arguments of others. This is why I think it's a mistake to found belief in very liberal free speech on the basis of the counterfactual idealizations to be off base. They aren't true and they make it too easy to argue against it. Why not just argue for the principle of the thing itself? (Not that I'm coming down on you here, just trying to explain why I find it weird).

It wouldn't be a counterexample to Darapti in Aristotelian logic, but that's because it makes the assumption that non-referring terms are to be disallowed in logic. And that seems strange nowadays since logic is viewed as being a very broad (maybe the broadest) abstract generalization and the properties we find in this 'follows from' relation. It seems like logic in the modern sense ought to work just fine whether or not the things actually exist, much in the way that mathematics is taken to be fine whether or not it corresponds to any sort of physical phenomenon.

But isn't that an empirical statement? What evidence/authority are you referring to when you say "It's understood as saying "There exists at least one unicorn and it is black""? I'm older than I care to remember and in my life experience people tend to guess the context from the language game. Unless you've got a longer life experience than me (unlikely, I'm ridiculously old), or some large sample evidence, I don't really see how you're in a position to say how an expression is 'normally' understood. — Isaac

I believe "There exists" is usually pretty unambiguous. Obviously a context can change that but it doesn't make it a valid argument to move from a category of things to saying there is some existing thing that's part of that category.

Hold up, you previously made the point that if the language doesn't make it obvious that it's not the real world which is the domain of discourse, then you shouldn't assume that it is. What does the term, "unicorn", suggest to you? Does he really need to explicitly say that he's talking about fiction? — S

What I said was that saying there is something that is such and such does not follow from talking about a category of things. Of course you can tweak what you mean but that's why I said one has to be careful or you'll make an invalid argument. Yes we know that people nowadays don't believe in unicorns and pegasi and that in normal speech (usually...) it's assumed to be fictional. But then if you formalized the argument from before on this basis, it would essentially be done in the way that affirmed what I'm saying, like so:

All fictional winged horses are horses
All fictional winged horses have wings.
There is at least one fictional winged horse.
Therefore some fictional horses have wings.

That's valid, but only because we've established a domain of things where it's clear the state of these existing things are different (they're fictional) and we've assumed there is some fictional pegasi. If you use an existential quantifier you should do so in a way that's clear about what you mean. It's an issue that exists, some have suggested adding an explicitly fictional quantifier for these situations. But the main issue is the argument form, not whether people believe the things they're talking about are real.

Maybe a real world example is needed so the fiction thing isn't a hang-up.

All forest people live in the forest.
All beasts live in the forest.
Therefore some forest people are beasts.

Even if the conclusion might be true today or at some point in the past, the issue is really how this is structured. We need to assert that there really is at least one such beastial person first. And that's the premise that will show whether or not the conclusion follows.

Unless you explicitly say you're speaking about some type of fictional scenario, no otherwise the statement is clearly false. It's understood as saying "There exists at least one unicorn and it is black". I didn't say it couldn't be understood but that it couldn't be rendered true under how we understand terms like "some" to work in normal contexts.

Nazism came to power because of limited free speech not because of free speech. — Harry Hindu

I don't even agree with dropping free speech but why would you say something so clearly false as a means to support free speech? Nazis came to power using street violence, inciting fear and unrest, and taking advantage of a more fragile state of the public mind after the first War and a terrible economy. Not because muh free speech was limited.

The question is, What do you mean by "harmful"? Nazi Germany had a robust economy before Hitler started WW2. The society wasn't harmed by fascism. Jews were, and any other group that wasn't pure German. — Harry Hindu

And Jews aren't part of the society? Further, how is the Nazi destruction of civil liberties and personal property not harmful? Like come on, everything you're saying is making hyper-idealized scenarios the reason why one ought to maintain free speech

MindForged seems to have gotten himself into if we simply think of the conclusion as relating to a possible or fictional world where it's true that some horses have wings? I mean, isn't that more charitable than assuming that an argument about winged horses is about the real world? — S

If one doesn't stipulated what domain of discourse one is speaking in (or if the argument doesn't make it obvious) then the assumption is that they're presenting a model of the real world. Like if I say "If Clinton had won the election, then x, y, z" I'm clearly talking about counterfactuals that might have happened. But since horses exist one has to be careful how they shift about the terms they're talking about because it can lead to this problem.

I was probably a bit abrasive. I'm just not a good communicator probably. I'll leave it to aletheist, lol.

That only contradicts the conclusion if the conclusion implies that winged horses actually exist. But that alleged implication is exactly what I'm calling into question. It certainly isn't explicit anywhere in the argument, as worded. It's your interpretation. Is your interpretation the only possible interpretation? No. It doesn't take a genius to think of other ways of interpreting the conclusion, as it is worded, which do not necessarily imply actual existence. — S

That's literally the standard theory of quantifiers used in virtually every modern deductive logic, whether classical, intuitionist, paraconsistent, or many-valued. That lends way more credence to the standard formalization of these terms than to an unspecified one which on its face leads to false conclusions. "Some" implies existence, because natural language terms like "some" are translated as "There is at least one blah blah such that blah blah". It's not that you cannot interpret these terms another way, it's that you cannot do so in a way that will actually capture a consistent formalization of how these linguistic features are used in reasoning. If I say "Some apples are delicious" everyone is going to agree I'm talking about actually existing apples and that there is at least one apple that is delicious because otherwise the assertion would be rendered false.

Only, it seems, if you equivocate between the premises to the conclusion. Like Terrapin said, you switch domains partway through the argument. You interpret the premises to be about an abstraction and about categories or sets, yet you interpret the conclusion to be about actual flying horses existing in the real world. It seems to me that it's your interpretation that's the problem, not the argument itself. You aren't interpreting it charitably. — S

I don't see where the hang -up is. Yes I'm switching domains, that's the point. That's what makes it fallacious. And how do we make it (the argument form) valid? As myself and aletheist (above) have said, you have to add a fourth premise asserting the existence (the actual existence) of a member of the set. Talking about sets of abstractions and then immediately concluding objects outside that domain of discourse populate that set does not follow in standard logic systems.

I told you that there is no "There is" contained in the wording of the argument, and that's true. I also said that you're reading that into the argument, which is also true. You can't fault me here. — S

"Some" is translated as "there is". There's only two kinds of quantifiers, and that's one of them. I can't be reading that into the argument if that's how virtually every logician is going to translate that argument.

That you can show me systems of logic where "some" is interpreted as an existential quantifier doesn't address the issue. Does it have to be interpreted in that way? If so, why? Is that the best or most charitable way to interpret the argument? If so, why? — S

The reason is has to be that way is because sets are not by default populated by members (sans the empty set). The only way for a set to be populated is the assert that it is so. The problem is the Darapti argument goes from talking about sets to concluding the set actually has members. It would be like making a conditional statement and then concluding the consequent without asserting or denying either of them first, e.g. If the Sun is out, then it is hot. Therefore it is hot. It's the same kind of mistake.

Then my queries would be regarding what's standardly done. Do you see that this is just kicking the can down the road? — S

You're not articulating an alternate theory (nor its pitfalls) or even showing that the standard theory comes out wrong. So I don't see how this is a real possibility to consider.

Why not? My understanding is that you say that this causes problems if you go by an interpretation that necessitates actual existence. But could it not be that the problem is with this interpretation? — S

Existential quantification asserts existence (or at least set membership; I'll skate by the latter). If you believe something different ought to be done then you'd need a new logic, or more likely, you'd just add a new quantifier but ti would be useless since it's not adding any new kind of way of talking about things. As the SEP says on it's page on quantifiers:

Much of contemporary ontology builds on the assumption that existence is to be understood in terms of quantification: in a slogan, to exist is to be something. Ontology is largely concerned with the domain of the existential quantifier. This assumption can be traced back to the work of Frege and Russell, both of whom analyzed quantification in terms of predication, and plays a crucial role in Quine’s admonition to transform ontology into the study of the ontological commitments of our global theory of the world regimented in the language of quantificational logic and identity.

It is possible that Russell is wrong, unthinkable as that might seem, yes? Maybe we could avoid the fallacy altogether with a different interpretation. Is Russell's the only interpretation? Are there no competing interpretations? — S

It's not just Russell, but Russell gave the clearest statement as to why. Russell can be wrong, but since virtually every logic understands quantifiers the same or in very similar ways that don't differentiate on this point, I don't see the critical error in just being careful how you use quantifiers.

The first two premises are about a conception; they're a priori claims about how you're using terms. They're not about the external world. — Terrapin Station

Well yes,that doesn't make them untrue in the external world, because then they'd be false which sounds incorrect. The terms have to have a definition.. And of course the argument uses variables. I'm just taking the general form of the argument and replacing the variables with consistent values across the different propositions.

I must be missing something obvious here or helse we just have different views about logical consequence. Cheers.

Except when you give the argument an interpretation, what makes a premise true is going to be some truth maker. We have a model (the real world) and in this model the first two premises are true. But the conclusion is false. This (finding a counterexample in an interpretation) is the most common method checking if a model is valid when doing semantic consequence, just check the SEP quote above. If a false conclusion follows from true premises (and we know those premises are true) it is invalid.

The model-centered approach to logical consequence takes the validity of an argument to be absence of counterexample. A counterexample to an argument is, in general, some way of manifesting the manner in which the premises of the argument fail to lead to a conclusion. One way to do this is to provide an argument of the same form for which the premises are clearly true and the conclusion is clearly false — SEP

Do you just object to model theory? It would be the same with just the syntax route.

No, on the contrary, if the premises are true, it follows that the conclusion is true. There is no counterexample to the conclusion of the argument under the assumption that the premises are true. You can't appeal to the actual world, because validity is about logical form, and soundness is about the actual world. You think that the article you quoted supports what you're saying, but it doesn't. You seem to be ignoring the premises and only looking at the conclusion. — S

The problem is the premises are true. Are you seriously denying that all winged horses are horses or that they have wings? If so then it has to be a terminological disagreement. Otherwise you're flat out wrong because no winged horses actually exist. The article I quoted does support me because the real world is a model in which the argument is proven to not be truth preserving. It goes from true premises to a false conclusion. The idea that the actual world doesn't count is absurd. We use logic to come to true conclusions about the actual world all the time.

You're not even quoting the wording of the argument, which is funny, given that you're the one who wrote it. There is no "There is" contained in the argument. You're reading that into it, which is the problem. — S

Read it again. "Therefore some horses have wings" uses existential quantification, that's what "some" is translated as in formal logic. I'm quoting myself correctly. There's no argument here, the argument is considered invalid by logicians for exactly this reason. It does not preserve truth in all models.

I grant that there might be a version of the argument where what you're saying applies, but that's a different argument to the one that you presented, and I don't agree that your interpretation is the only possible way that the argument can be interpreted. The wording is ambiguous. — S

The wording is only ambiguous if you don't interpret the logical terms as they standardly are done. "All" is universal quantifying, "some" is existential quantifying. You cannot validly move from quantifying over a set to saying the set has members who satisfy the conditions to be part of the set. That has to be an extra premise otherwise it commits the existential fallacy. Unless I'm much mistaken, this is the exact argument Russell gives to show why modern logic does not admit this as a valid form.

In which case saying anything about winged horses puts us in the domain of things that we're imagining. If we change domains midstream we're equivocating. — Terrapin Station

That's more or less what I'm saying. That's what makes it invalid. The class can't be assumed to have members unless we state that it does. Aristotle didn't see this as a problem because he thought logic ought only consider classes with known existing members, but that's not assumed in mathematical reasoning nowadays. It's too limited.

That's not how validity works. — S

um, no. Validity is defined as truth preservation over all cases. As we know the first two premises of the argument are true, yet the conclusion is false, we know the issue has to be with the form of the argument. It's invalid, in other words. As the SEP article in logical consequence says:

The model-centered approach to logical consequence takes the validity of an argument to be absence of counterexample. A counterexample to an argument is, in general, some way of manifesting the manner in which the premises of the argument fail to lead to a conclusion. One way to do this is to provide an argument of the same form for which the premises are clearly true and the conclusion is clearly false. Another way to do this is to provide a circumstance in which the premises are true and the conclusion is false. In the contemporary literature the intuitive idea of a counterexample is developed into a theory of models. Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language. Given a model for a language one is able to define what it is for a sentence in that language to be true (according to that model) or not. So, the intuitive idea of logical consequence in terms of counterexamples is then formally rendered as follows: an argument is valid if and only if there is no model according to which the premises are true and the conclusion is not true. Put in positive terms: in any model in which the premises are true (or in any interpretation of the premises according to which they are true), the conclusion is true too.
— SEP

Soundness is about actual truth or falsity. Validity is about assumed truth or falsity. In your example syllogism, under the assumption that the premises are true, it follows that the conclusion is true. Hence, the syllogism is valid. — S

It does not follow. If I assume all winged horses are horses and all winged horses have wings, we cannot infer that some horses have wings because we see in the actual world that the first two premises are true yet there are no winged horses. This argument form is known to be invalid in classical logic, it commits the existential fallacy. To make it valid you need a fourth premise that explicitly states that there is at least one existing winged horse. But then we see exactly why the original argument form was invalid.

You're jumping ahead based on your own assumptions. I'm questioning these very assumptions of yours. You're begging the question. — S

What? How am I begging the question when I just stating the definition of semantic logical consequence?

Why do you think that it must be interpreted in that way, as implying existence? In English, as opposed to symbolic logic, and worded as such, it is more ambiguous than you're making out. — S

Because "There is" is more or less always interpreted as an existence claim. We're talking about formal logic, not informal natural language reasoning.

!!! oops, that was supposed to say n x 2 = n + n. Mea culpa.

Anyway, what I'm saying is there doesn't need to be anything that instantiates this for us to reason about it. For Aristotle, logic is supposed to be used for things known to exist. In the above, "For every" is just the universal quantifier yes? That's before the predication. But surely it's fine to reason in mathematics without assuming something in the physical world corresponds to this? (Obviously it does in this case but pure mathematics isn't guaranteed to)

Why would you define an abstract operation, and moreover assign "true" to it (assuming we can even really make sense of that), if it can't be satisfied by anything we plug into the variable (in whatever domain you're working in)? — Terrapin Station

I didn't say it couldn't be satisfied, what I said was that quantifying over all the elements of a set does not entail the set has members who exist (that's a separate set). Winged horses could exist but they do not. So given we know this we infer the invalidity of form. The reason I keep repeating this was because way back you seemed to be saying it was valid:

It does, though. It's the same as "All silver toasters are toasters. All silver toasters are silver. Therefore some toasters are silver." — Terrapin Station

What? It seems to me that if the premises are true, then the conclusion must also be true. It logically follows. — S

Unless you can point to where the winged horses are you cannot say it's valid. If the conclusion of an argument is false in spite of true premises, then the argument for is invalid. There is thus a model where truth is not preserved, that's the definition of an invalid argument.

But that wasn't in the argument, and it doesn't seem appropriate to interpret the argument in that way. — S

"Therefore some horses have wings" has an existential operator, how is that inappropriate to point out when it creates a false conclusion from true premises?

Can you give any examples where this issue would be important? — Andrew M

Any time one uses the universal quantifier I would think. "For each natural number n, "n x n" = "n + n". That does not assume there is some existing n, it's just a statement about how to define an abstract operation, whether or not that holds in the physical world. If quantifying did assume existence we'd expect to see, I dunno, every number be instantiated by some collection of elements or weird alegbraic models have mapped onto real things, or every kind of geometry have a corresponding universe modeled on it, wouldn't we?

To me it seems analogous to "The King of France is bald". Note that Russell and Strawson disagreed on how to treat this kind of statement, with Strawson defending the view that the presupposition fails (and thus the statement is neither true nor false). — Andrew M

Well OK, there is a debate here but I'm of the view that one ought to try and use as few different logics as possible. I'm not familiar with what Strawson said here but Russell's general route seems correct (use classical logic if it can give a good answer), though I don't think I actually accept his theory of descriptions to resolve these.