Comments

  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Both make use of the very same rule for quantifier introduction.

    D says that this is a table; P says that this is not a table. D can introduce a quantifier so: This is a table, therefore there are tables; tables exist. P introduces a quantifier thus: For any item you choose, it is not a table, therefore there are no tables, tables do not exist.

    They can agree that the argument the other presents is valid, but disagree as to the premise, and so as to the conclusion.

    Notice that they are both using natural deduction of the first order; they are using the very same logic.


    Hence calling their difference a quantifier variance is misleading. They are taking the same logic and applying it to a different range of things.

    This thread seems to have run its course.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    There is no definition in the quote you cite.

    Elsewhere:
    DKL: “There exist tables”
    PVI: “There do not exist tables”
    The deflationist: “something is wrong with the debate”
    — p.3
    DKL includes tables in his domain. PVI does not. Both make use of the very same rule for quantifier introduction.

    No case has been presented for a variance in the quantifier introduction rules, as opposed to a variance in the domain.
    Banno
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    No, it doesn't.

    An adequate explanation of "what quantifier variance is" would show the difference between at least two forms of quantifier. The quote says that there are two differing forms of quantifier, but does not say how they differ.

    Folk hereabouts can verify this for themselves.

    Whether there is a better explanation elsewhere in the text remains undecided.

    Elsewhere:
    DKL: “There exist tables”
    PVI: “There do not exist tables”
    The deflationist: “something is wrong with the debate”
    — p.3
    DKL includes tables in his domain. PVI does not. Both make use of the very same rule for quantifier introduction.

    No case has been presented for a variance in the quantifier introduction rules, as opposed to a variance in the domain.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Never seen one.fdrake
    After thinking on it, it seems not to be a possibility.

    But you do so in natural language. So you don't care about the underlying formal logic.fdrake
    Indeed, since Universal Generalisation is taken as granted in first order logic. The formalisation is trivial.

    Since if even mathematical reasoning has both ambiguity and commonality regarding the underlying logic and its quantifier introduction rules, why would we expect logic to behave as more than a prop, crutch or model of quantification in natural language? Never mind ontology!fdrake
    Formal logic can serve to clarify usage in natural languages. The primary case being how first order logic sets out and separates the three uses of "is" - predication, quantification and equivalence.

    I still do not think that a sufficient case had been made for quantifier variance. We could not have two languages that talk about the same thing but which differ only in the way they introduce quantification. Generalising that, we could not have two languages that vary only in how they quantify, without their also varying in their domain.

    The metaphysical notion (@Count Timothy von Icarus) grounding this is that logic can have no ontological implications. Logic does not tell us how the world is. I suspect you will agree with this.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    That quote does not set out what quantifier variance is. It merely stipulates that DKL - David Lewis - and PKV - Peter van Inwagen - mean different things by "exists". Simply asserting that there is quantifier variance is not explaining what it is.

    The article can be found here.

    The last few pages of the article are worth a read.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Yeah, I like it, it's a bit divergent, but on topic. "Any particular man is mortal" introduces a quantifier almost obliquely. In first order logic it would be parsed "For all x, if x is a man then x is mortal", but now I am wondering if there might be an alternate parsing in some alternate logic.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff

    Cool. Took me a while to catch on. My apologies. So
    that is, "...for arbitrary a..." just is "for any a you might pick", or "for any a" - it's introducing a quantifier.Banno

    This is pretty clear: How Universal Generalization Works According To Natural Reason Salient is that the item chosen as the exemplar could have been any particular x in S. One can't conclude from "Socrates is mortal" that "all men are mortal", but one can conclude from "Any particular man is mortal" that "All men are mortal".

    But I'm not sure how this relates to
    How would you account for people's differences in use?fdrake
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    You haven't interacted with any of this.Leontiskos

    I think this is the first time that paper has been quoted in this thread.Leontiskos

    So you haven't been reading my posts. Fine.


    In what salient way is logic like chess? Why would we assume such a thing? Chess is just a made-up game we created to have some fun and amusement.Leontiskos
    and logic...
    :wink:
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    fdrake has been consistently talking about intensional differences in quantifiers, namely by way of introduction and elimination rules for quantifiers.Leontiskos

    Has he? Ok. So what are these "intensional differences in quantifiers"? How are you using "intensional" here? How does that play out?

    How do introduction and elimination rules differ in intensional logic?

    And, significantly, classical first order logic is extensional.

    So fill that out; what are your intensional introduction and elimination rules for quantifiers, and how do they differ from extensional introduction and elimination rules for quantifiers?

    Fill it out.

    Just to be clear, here's the extensional intuition behind quantification:
    If our domain is {a,b,c} then "U(x)fx" is just "fa & fb & fc"; and "∃(x)fx" is just "fa v fb v fc".Banno
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    How does translation play into it here?fdrake
    Well, that's what I'm asking, by way of answering this:
    The challenge I see that presenting is that people can believe statements that block applications of inference rules, or otherwise not believe in appropriate inference rules. Even when two people share the theorems of the underlying logic... You just have to hope that every person innately believes every theorem. If they don't use the quantifiers in the same way, they don't have the same intensions over people.fdrake
    I'm still wanting an example of where quantifier variation is not also domain variation. I don't think it can be done - quantifier variation just is domain variation.

    That is, you asked me
    How would you account for people's differences in use?fdrake
    And my answer remains, perhaps they are talking about different domains.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    You can introduce the quantifier onto (Pa->Qa) to get (for all x P(x)->Q(x) ) if you made no assumptions about a anywhere in your reasoning.fdrake
    Hang on.
    (Pa→Qa) → (∀x (Px → Qx) is not valid.
    How does "if you made no assumptions about a anywhere in your reasoning" change this?

    And P( a )→ ∀xP( x ) is also invalid.

    If "a" is arbitrary, doesn't that just make it a variable instead of an individual? Sure, ∀yP(y)→∀xP(x) is valid.

    I remain lost.


    Edit: that is, A→B gets parsed into predicate calculus as (∀x(Px→Qx)), not as (Px→Qx). Leaving out the quantification is not using a different quantifier...?

    Second edit; that is, "...for arbitrary a..." just is "for any a you might pick", or "for any a" - it's introducing a quantifier.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    The challenge I see that presenting are that people can believe statements that block applications of inference rules, or otherwise not believe in appropriate inference rules. Even when two people share the theorems of the underlying logic... You just have to hope that every person innately believes every theorem.fdrake
    I'm not sure I follow what you are suggesting here. Yes, sometimes folk make invalid inference, or fail make valid inference. But in order to recognise this, we must understand the distinction between valid and invalid inference.

    In order to recognise a failure of translation, you must have an idea of what success would look like.

    (P(x)=>Q(x) where x is arbitrary lets you derive (for all x P( x ) => Q( x ) ), and they can'd do that).fdrake
    It might but I don't see that it does - those unbound variables make it hard to see what is going on here. But (Pa→Qa) does not allow (∀x (Px → Qx))... You've lost me.

    Thanks.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Logic is not just a stipulative game, like chess. The analogy doesn't work.Leontiskos
    Can you set out why or how the analogy does not work? In what salient way is logic not a game of stipulation?

    And as I said, if you embrace logical pluralism then it doesn't matter how you quantify or which logic you use, for everything is stipulation and no one stipulation is any better than any other.Leontiskos
    Why doesn't it matter how you quantify or which logic you use? Isn't that of the utmost import? That there are multiple logics does not imply that they are all of equal utility or applicability. Propositional logic will be of little help with modal issues, and modal logic might be overkill for propositional problems. Some art is involved in the selection of a logic to use.

    ...within a single logic qualitative differences of domain reflect qualitatively different understandings of quantificationLeontiskos
    What? For example, how could a "qualitative" difference in domain in a first-order logic lead to a difference in quantification? The quantification rules are defined extensionally.

    I honestly do not follow what you are claiming here.

    Quantifiers are not subject to second-order equivocation; therefore QV failsLeontiskos
    Seems to me that such equivocation is still about the domain. I think I showed that , above. Can you show otherwise?
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    I'll add that the above seems to me to be much the same point as that made here:

    Those quantifiers are introduced differently, and as the paper "Quantifier Variance Dissolved" notes that provides a strong argument for a form quantifier variance without a reduction of quantifier meaning to underlying entity type it quantifies over, and without committing yourself to the claim that there's a whole bunch of equally correct logics for the purposes of ontology.fdrake
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    the sort of assertions you get when you try to squeeze a big set of phenomena into a tiny box of explanation.Count Timothy von Icarus

    I was thinking something not too dissimilar; that there is an approach to doing philosophy that looks only at the large scale, using a big brush, and in doing so paints a misleading picture.

    Seems to me that this is part of the disagreement - so far as there is one - in these pages.

    At the very centre of this thread is the question of what quantifier variance consists in. And it seems to me that those who advocate quantifier variance as a way of explaining broad-brush disagreements have a vested interest in never quite answering that question explicitly, while those who dismiss quantifier variance perhaps take on too tight an explication.

    Hirsch & Warren make it clear at the bottom of Page 2 that their topic includes the rules of quantifier introduction:
    No doubt the inferential role of “there is” or “exists” in natural language is more complex than the role of “∃” in formal logical languages, but the formal-syntactic role of “∃” provides a tidy approximation of the informal inferential role of “exists” or “there is” in English. The expression “there is” is an existential quantifier, in English, roughly because for name “a” and predicate “F”, from “a is F”, “there is an F” follows; and if a non-“a” claim follows from “a is F”, with no auxiliary assumptions made about “a”, then that same thing also follows from “there is an F”. Expressions that obey this role unrestrictedly, for all names and predicates that could be introduced into the language, express the language’s unrestricted concept of existence.
    The paradigmatic example is existential generalisation, f(a)⊢∃(x)f(x). The claim is that Universal Instantiation, Universal generalisation, Existential Instantiation and Existential generalisation have differing uses in different logics. And indeed, these do vary in form from one logic to another.

    So in second order logic - an infamously burdensome topic - existential generalisation is something like
    f(a)⊢∃(X)X(a). So in second order logic we can conclude validly, from say "the shoe is blue", that the shoe has some property. Notice well the difference here, between generalising over the individual, "a", and generalising over the predicate, "f".

    (I am only making use of second-order logic here because others have made mention of it, and yet it was unclear from the context what they were attempting to do with it. The argument seemed to be along the lines of "there are instances of second order logic, therefore quantification varies", which just does not work.)

    Now look at the difference between these two examples of existential generalisation. They are different. And yet they are recognisably both instances of the application of the same rule.

    Hnece Finn and Bueno can say, correctly,
    We argue that ∃ always has this role, as it invariably has the function of ranging over the domain and signaling that some, rather than none, of its members satisfy the relevant formula. Yet the quantifier-variance theorist requires ∃ to have multiple meanings.Quantifier Variance

    While I was typing this, gave yet another examples of where quantifier variance is variation in the domain.

    Now I am quite happy to agree that domains vary. But I am far less incline to agree that these are instances of a variation in the quantification rules themselves.

    And I think Srap was quite right that we might progress if we head back towards the principle of charity. I stand by what was claimed in the second post here, that the most telling objection to quantifier variance is that we do indeed translate (make use of) what we loosely call different languages. It seems to me that attempting to explain this by introducing "quantifier variance", and not being clear as to whether we are talking about changes in domain or changes in quantification rules, is doing us a disservice.

    This by way of attempting to use a fine brush to keep some of the discussion on the titular topic.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    I think we are largely on common ground then.Count Timothy von Icarus
    I'd be surprised if there were a substantive difference.

    We should explore whether the "three main flavours" are properly independent. To my eye the third, "Logic is a principle at work in the world, its overall order" might well be an illusion that drops out of something like the first, that logic is working through, formally, what we can and cannot consistently say.

    Pressing the chess analogy further, the third is as if a child marvelled at the fact that one bishop always stayed on the red, and one on the white, and supposed this to be "a principle at work in the world" or perhaps posited some transcendent force that makes it so, rather than seeing a consequence of the rules.

    Metaphysics can be seen as the discussion of the background against which talk of the physical world can take place. I've Watkins and similar in mind, explicating the logical structure of conservation laws and so on. The more speculative types of metaphysics are best left to themselves.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    I dunno OLP heads, "is" sure crops up in a lot of language games with different grammars. Almost as if there are different uses of it!fdrake

    Can we list them? We have the is of predication: the cat is black; the is of quantification: there is a black cat; and the is of equality: The cat named Tiddles is the cat named Jack.

    There might be more. First order logic at least allows us to differentiate these three.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff

    Why do Bishops move diagonally?
    This piece originally began life as a symbol of the elephants in the Indian army. It's original movement was 2 squares diagonally in any direction. It was a piece of only moderate power.

    It was only when the game was carried to Europe that it's fortunes began to improve. The Europeans were not as familiar with the elephant as the Indians so they needed to change the piece to something that people in Europe could relate to. The church was very powerful in Europe when these changes were going on. It's influence on political life in the Middle Ages was recognized when the piece became a Bishop.

    The Europeans also wanted to speed the game up as they found it laboriously slow. The Bishop was one of a number of pieces to see it's powers increase, gaining unlimited range on the diagonals.
    This bit of history only partially answers the question. It remains that we might move bishops anywhere we like on the board, but to do so would be to cease playing chess, or at the least to play it differently. There is a way in which the answer to "Why do Bishops move diagonally?" is, that is just how the game is played, that its what we do. Seeking further explanation is redundant.

    Could we change the way we use quantification in logic? Sure, why not. Indeed quantification is done slightly differently in each of the various logics. As the domain changes. I don't believe what I have said commits me to logic being "eternal and unchanging". The way quantification works changes as the way the domain works.

    if one attempts to quantify over all mammals but omits unicorns because they were not known to exist (or vice versa) then a quantitative difference of domain results in a merely artificial difference of quantifier-qua-extension. But if one attempts to quantify over all things but omits universals because they are a nominalist (cf. QVD 295) then a qualitative difference of domain results in a substantial difference of quantifier-qua-extension.Leontiskos
    What? I can't make anything of this, nor much of what follows. Talk of nominalists and universalists seems oddly anachronistic.

    Whatever point you are making remains unclear. If you wish to talk of changes of domain as changes in quantification, go ahead, but that seems to me to obscure more than it reveals. I'll leave you to it.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    I agree with much of this post.

    One can't count things unless there are things to count. But it cannot follow that there being things logically precedes there being numbers of things. This is not asking which came first, the chicken or the egg, it's asking which came first, the egg or the egg.

    Language is not games all the way down; at some point one must recognise that this is just what we do.

    Use itself doesn't float free of the rest of the world.Count Timothy von Icarus
    Sure. I don't believe that what I have said implies otherwise. language games are embedded in the world. What was novel in their introduction is the idea that we do things to the world by using words.

    It's not that the world is already quantified - divided into subjects and predicates - nor is it that we might quantify the world in any arbitrary way and achieve much the same result. We stipulate the way things are, in a way that is restricted by how things are.

    The question of which came first does not have application here. Nor is the historical development of these considerations relevant. Again, it's just what we do.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Now how exactly do we manage that? Attributing a predicate to an identified individual looks straightforward, but in ordinary life we only reach for the existential quantifier in the absence of such an individual. (One of you drank the last beer. Someone left these footprints. There's something really heavy in this box.)Srap Tasmaner

    There is an x such that x drank the last beer.

    There is an x such that x left these footprints.

    There is an x such that x is heavy and x is in the box.

    All standard first order stuff.

    Not seeing an issue.

    Is there an x such that x will pry open the draw? First order.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    What is your point?Srap Tasmaner
    What's my point?

    Is there a substantive disagreement here? If so, what is it?

    (Edit: I posted that previous comment before finishing it, then lost the edits. I've not much more to add, but will repeat the point that what quantifier variance amounts to remains, at least for me, either trivial or ambiguous. )
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Can you think of an edge case where it's not clear whether something counts as a berry?Srap Tasmaner

    Strawberries don't count as berries when one is doing botany. They do not grow from a single ovary. But if folk order berries and cream, one might expect strawberries in the bowl.

    So do we have two incommensurable languages, the one in which most folk are happy with a bowl of strawberries and blackberries, and the other in which the botanist expected the bowl of berries to consist of grapes and bananas? Well, no. We understand the difference between doing biology and ordering breakfast.

    The things in the world do not change between the lab and the dining room. The way we use the word "berries" is what changes. Not the way we use "is".

    So we perhaps agree that "quantifier variance" is a poorly chosen term; and that what we do is more significant than what we say.

    The rest looks to be hokum.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    As it happens, this is what the thread should be about.Srap Tasmaner

    Yes, indeed. Thanks for the link, which I will take on notice.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    What I am objecting to is an explanation that seems to say that prior to an act of counting there is nothing that affects how counting is done.Count Timothy von Icarus

    The berries are there, counted or no. Those berries can be divided evenly. Dividing berries evenly is something we do to the berries. The direction of fit is that we change the world from a bunch of berries to two bunches of berries.

    Why would they be counted as such? Because that's the way "eight" is used. How is this explained without reference to the 8 berries existing prior to counting? There are presumably eight berries before they are counted.

    And yes, it isn't the case that numbers just are actions, they also determine actions. You can't divide seven berries evenly without making a mess. Language games are not just words, they are things we do in the world with words.

    And I do not want to say ""numerically discrete entities exist prior to counting", because that seems to be quite an odd thing to say. I will say that there were eight berries before they were counted. And this will have been so, regardless of any perception.

    Keep going. This is interesting.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    what explains this?Count Timothy von Icarus
    Pretending 8/2 = 5 won't get you very far. You will not be able to divide the berries between two people fairly. It will be functionally inadequate. It won't work.

    Edit:
    To put it otherwise, and bring my last two posts together, thinking you can start with eight berries and from that give five to each of two different folk is to misunderstand how "eight", "five" and "two" are used.

    It's not to misunderstand eternal universal facts about platonic forms.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    If some society somehow stipulated that 8/2 = 5, we tend to feel we could give them a good demonstration of why this is not the correct way to do division.Count Timothy von Icarus

    Wouldn't you conclude that one of the terms had been mistranslated? Perhaps "8" was their symbol for 10, or "5" their symbol for 4.

    That is, we might apply the Principle of Charity and assume that what they said was correct, interpreting their utterances accordingly.

    That such things are stipulated does not mean that they are arbitrary.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff


    Cheers, Wayf. Keep trying to say more than can be said.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    The attempt to reduce mathematics to 'speech acts' is inadequate to account for the 'unreasonable effectiveness of mathematics in the natural sciences'Wayfarer

    You don't need to go all quantum to say "mathematical constructs can correspond to real physical entities". The three sticks will do exactly that. And it's not magic that seven sticks take away four sticks is three sticks. Dirac's derivation is no more than that. You talk as if his calculations brought antiparticles into existence. They didn't. They allowed for a conversation about antiparticles, inspiring folk to take a look for them. It's no more mysterious than looking for the three remaining sticks.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    But just stating the trivial fact that "numbers are something humans use," or "words are things we say," as if this pivot to activity makes the explanation an unanalyzable primitive strikes me as essentially a non-explanation.Count Timothy von Icarus
    There is a bit more going on.

    Our issue was, what sort of things are numbers? And one answer is that they are real, like trees, sticks and rocks, but that they are in a special world that makes them unavailable for examination in the way that trees and sticks are available. Roughly, Plato's world of forms.

    The alternative on offer is that numbers are a way of treating the things around us. Choosing three sticks is an act directed at the sticks, whether done by a human or by a crow.

    Humans have a capacity to extend this process using words. A crow might be able to decide to collect three sticks, but is not able to decide to collect three sticks next Tuesday.

    The human world is suffused with creations of our language. This piece of land counts as your property. This piece of paper counts as five dollars. Your making certain utterances counts as giving an order or asking a question. Property, money, orders and questions are parts of our world, yet we do not expect to bump in to them in the way we might with sticks, trees and rocks.

    This counts as three sticks. That counts as four sticks. Together they count as seven sticks.

    And we build on this. "7" counts as seven, and with a few extras we can write "3+4=7". These count as numbers. A shape with three sides counts as a triangle. And so on, the whole edifice of Maths being built on working out how we can treat these things in a consistent way.

    And all without needing Plato's magical realm. Just as our shared intent towards the piece of land makes it count as property, and our shared use of the piece of paper makes it five dollars, our shared use of "seven" makes that seven sticks, seven dollars, or seven triangles.

    There are no dollars or property without our using paper and land in a certain way. There are no numbers without our using the things around us in a certain way. It's not just that numbers are things we use, but that our using them is what they consist in. Same for words.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    The next step in the argument is to supose that a difference in domain just is a difference in the definition of the quantifier, that since Ǝxf(x)=df (fa v fb v fc...)* any change in the domain is a change in the quantifier. That's addresses in section two of the article.

    In the example of the paining of an apple, it amounts to our attempting to resolve the issue by combining the two domains of the two folk in the room. Do we list the item in the corner as an apple or as a paining? But notice that this is not a decision about quantification, but a decision about what is included in the domain.

    Of course, if we allow for a maximal domain, a domain containing everything, then there can be no such variance:
    It is unclear that there is a coherent way of formulating any such quantification and the resulting maximal domain. If the maximal domain is a set, then unrestricted quantification would require quantifying over everything, and there would have to be a set of everything, including, in particular, a set of all sets, among other inconsistent totalities, since all of these things are in the scope of an unrestricted quantifier: everything is in its scope, after all! But that is clearly inconsistent. — p.294

    And we come back to the main objection: the lack of a coherent explanation of what "quantifier variance" might be.

    *That is, "something is f" means by definition that individual a is f or individual b is f or... for all the individuals in the domain.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Maybe the proponent would take each person, sit them in the same room, and ask them to evaluate the sentence < Ǝx(R(x) ^ A(x)) > (“There exists an x such that x is in the room and x is an apple”). In the corner of the room is a painting by Cézanne, and within the painting is depicted a paradigmatic red apple. One person says that the sentence is true and the second person says that it is false. Upon inspection we realize that the disagreement is not over whether the painting depicts an apple, but is instead over whether the quantifier captures it as an apple. Specifically, it is over whether an imaged thing exists through the image. This is an extensional evidence for quantifier equivocation, different from fdrake's intensional evidence. The paper itself admits this possibility. It begins an argument:Leontiskos

    Nice example. The issue is whether ƎxA(x), whether there is something that is an apple in the domain. The existential quantifier plays out as a disjunct of the domain. List all the items in the domain, and if any one of them is an apple, then the existential quantifier will be true.

    The two folk in your example agree with this definition of quantification.

    If the painting is an apple it will be true, if not, it will be false. That is a difference in the domain, not in the definition of the quantification. One domain includes a painting, the other an apple.

    The two folk disagree as to the domain.

    This is not an example of quantifier variance. It is a disagreement as to the domain.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Now, if you want to say "numbers are a human invention," that seems like fair game. But there has to be some sort of explanation of their usefulness and development across disparate, isolated societies.Count Timothy von Icarus
    If you want to say "nouns are a human invention," that seems like fair game. But there has to be some sort of explanation of their usefulness and development across disparate, isolated societies.

    Will we say that the world consists of objects, and we just give them names? Or will we say that the names are arbitrary, we just invent them?

    Is the world already divided up, or do we divide it up arbitrarily? But that's a false dilemma. carcinization works.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Ho hum
    .
    Another point that seems to need reinforcing is the nature of quantification. If our domain is {a,b,c} then "U(x)fx" is just "fa & fb & fc"; and "∃(x)fx" is just "fa v fb v fc". If the domain changes to {a',b',c'} then "U(x)fx" is just "fa' & fb' & fc'"; and "∃(x)fx" is just "fa' v fb' v fc'". That is, the definition of each quantification doesn't change with the change in domain; but remains a conjunct or disjunct of every item in the domain.Banno

    Now to be sure there are issues when applying this to quantification in modal logic. But those issues are to do with the nature of the domain, not the nature of quantification. They concern whether a,b,c... are the unique to each possible world or alternately if say "a" can refer to a in any possible world in which a occurs, and so on.

    There are different ways of applying quantification in modal logic. But each is a way of applying quantification, not a different way of quantifying. Which is "correct"? Well, asking that question that shows a fundamental misunderstanding of the nature of logic. Which is "correct", French or German? Better to ask which is more appropriate, or more useful in a given situation.

    Let's add Gillian Russell to the mix: Logical Nihilism: could there be no logic?. Lemma incorporation is also preferable to monster-barring, in which Russell argues that ad hoc logical pluralism to be preferable to both arbitrary monster-baring and to nihilism.

    Specifically,
    ...quantifier variance is not meant to entail a multiplicity of logical systems, each with its own quantifiers and conception of validity, but rather it requires that, within a single logic, there should be multiple (existential) quantifiers operating differently. And so, logical pluralism should not be equated with quantifier variance, as having a choice between logical systems is not the same as having a choice of quantifier meaning within a system of logic. — Quantifier Variance Dissolved

    There remains a difference between quantification and ontological commitment that is not recognised by quantification variance. Quantification sits within a logical system, ontological commitment remains external to logical systems.

    Logic gives us a variety of ways in which we might talk about how things are. It does not commit us to this or that ontology.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Oh, and this bit is salient:

    What all of this illustrates, is that in tying quantification to existence, two distinct roles are ultimately conflated:
    (a) The quantificational role specifies whether all objects in the domain of quantification are being quantified over or whether only some objects are.
    (b) The ontological role specifies that the objects quantified over exist.
    These are fundamentally different roles, which are best kept apart. By distinguishing them and letting quantifiers only implement the quantificational role, one obtains an ontologically neutral quantification. Ontological neutrality applies to both the universal and the particular quantifier (that is, the existential quantifier without any existential, ontological import).
    Quantifier Variance Dissolved
    And the conclusion to that section,
    However, once again, no variance in any quantifier is involved.

    , it seems is talking about some supposed ontological role, the E, not quantification, ∃.
  • Quantifier Variance, Ontological Pluralism, and Other Fun Stuff
    Knowing what mathematics is seems like one of the biggest philosophical questions out there. Not to mention that a number of major breakthroughs in mathematics have been made while focusing on foundations, so it hardly seems like a useless question to answer either.Count Timothy von Icarus

    Sure. I don't see how what I have said counts against this. Maths as a language, a set of (or sets of) grammatical rules that set out what we might consistently say.

    Why this huge difference?Count Timothy von Icarus
    Good questions. The property analogy will only go as far as "counts as..." or "as if...". And as I've said, we do treat numbers to quantification, equivalence and predication - all nice neat uses of "is". Numbers are in many ways not like property.

    So where would causation fit here? I don't see that it does.