Possible Worlds Talk

First, it is unnecessary. As we can have no epistic access to any world but our own, actual world, anything we can learn, we can learn from the real world.

Second, if the purpose of possible worlds talk is to define the meaning of modal statements, it is circular. If a person does not understand modality, they will not understand the meaning of "possible worlds."

Third, speaking of worlds as simply "possible" allows one to confuse logical, physical and ontological possibility.

If possible worlds talk is nonsense, then rigid designators are undefined.

We don't even have direct access to our own world, so are we able to learn anything about the actual world?

Yes modal semantics are used to define modal terms like "possibility" and "necessity" and the like. That doesn't mean you cannot understand what possible worlds are, they are part of how you define the terms. How does this even follow? I could just call them "alternate world" and use the same definitions of these terms, so surely the argument isn't that the world "possible" is used to refer to these.

Then just stipulate what type of possibility intended. This doesn't seem like a real worry.

If possible worlds talk is nonsense, then rigid designators are undefined.

Um, didn't the SEP define it in your quote?

For example, an object's modification of our sensory state is identically our sensory representation of the object. As one state belongs both to the sensed object and to the sensing subject, there is an existential penetration, not a gap.

If you do not understand "possible" or "necessary" you will not understand "possible world."

I do not define "possible" in terms of worlds. P is possible if P does not contradict the set of propositions which it is possible with respect to.

Further "alternate world" does not mean "possible world." I may imagine any number of alternate worlds that are not self consistent, and so impossible. If you want to bring in the concept of self-consistency, you may, but then you're not defining modality in terms of a set of worlds, but following my definition of the last paragraph.

Yes, it is, because it leads back to circularity. To define any type of possibility you must specify what makes a world "possible" in that way -- which means that you need an independent definition of that mode of possibility -- in other words, the worlds cease to be a primitive, and are merely an unparsimonious wart on your theory.

Now you can say that "Hesperus" and "Phosphorus" are "rigid designaters," but there is no intelligible property that allows us to determine one way or the other if they are.

Is there an a priori possible world in which one planet appear in the sky in the evening and another in the morning? I don't see why not

Clearly, the conclusion is nonsense, because "necessarily," does not even follow the norms of possible worlds talk. There are many worlds that seem perfectly possible where this is not so, but they are excluded by hypothesis and arbitrary dictate.

Is there an a priori possible world in which one planet appear in the sky in the evening and another in the morning? I don't see why not. It might be argued that such a world would violate some law of nature, but the laws of nature are known a posteriori. So, if you use this argument, "Hesperus is identical with Phosphorus" not by necessity, but contingently.

So, Kirpke is pulling a swindle. There is nothing about "Hesperus is identical with Phosphorus" that makes it anything but contingent. "Hesperus" does not mean "Venus." it means a planet seen in the evening, which we have since identified as Venus. Similarly, "Phosphorus" does not mean "Venus." It means a planet seen in the morning, which we have since identified as Venus.

Now you can say that "Hesperus" and "Phosphorus" are "rigid designaters," but there is no intelligible property that allows us to determine one way or the other if they are. Then, you can hypothesize people in all possible worlds will apply these terms as we do. Again, there is no factual basis for doing so. Then, because of these arbitrary and baseless constructs, you can say that "Hesperus is identical with Phosphorus" is necessarily true.

Clearly, the conclusion is nonsense, because "necessarily," does not even follow the norms of possible worlds talk. There are many worlds that seem perfectly possible where this is not so, but they are excluded by hypothesis and arbitrary dictate.

If a person does not understand modality, they will not understand the meaning of "possible worlds

My understanding is that the modality the possible worlds paradigm seeks to explain is not the fancy modality of modal logic, but the modality of everyday speech, when we say something is possible, impossible or certain.

There's no need for possible worlds in that interpretation. I can't personally see any value in the possible worlds paradigm.

I am pretty confident that, given the choice between my interpretation and one involving all the metaphysical baggage of the possible worlds paradigm, that average person would say that mine is the closest to what they meant.

That example is of something nobody would ever say and expect to be taken seriously. I don't regard the lack of applicability to something nobody would ever seriously say as any reason to discount a definition.

There's no possible way to justify this, you only have access to your perceptions.

The world of perception is not identical to the world itself.

Possible world's really just a tool to explain set of concepts.

I do not define "possible" in terms of worlds. P is possible if P does not contradict the set of propositions which it is possible with respect to.

That isn't an explanatory definition at all. You just defined possibility and used possibility within the definition.

It means the same thing if I define that way.

The issue is you getting hung up on the word possible appearing in the name of the concept.

The criterion of consistency doesn't favor your definition at all because it was a circular definition.

Lack of parsimony as compared to what?

Not only are the usual definitions of the various modalities almost exactly as you defined them in your post

No intelligible property? Seriously? So taking a particular path in the sky, being the second planet from the Sun, having a particular level of brightness, having a certain atmospheric composition (etc) are unintelligible properties? The whole point is that we are talking about worlds in which Venus (and the solar system) exists and that the identity statement "Hesperus is Phosphorus" is therefore necessarily true because they pick out the same object *in worlds where the relevant objects exist*. So when you say things like this:

Possible worlds are pieces of a technical apparatus that allow a model-theoretic interpretation of a language with modal operators. They have no metaphysical or ontological import in of themselves – only a supplementary theory as to what they are intended to model can provide this

There's no need for possible worlds in that interpretation. I can't personally see any value in the possible worlds paradigm.

Well the value is giving real, rigorous definitions of these notions that allows us to be confident in using them in theorization.

Dfpolis: you can stop writing paragraphs and paragraphs of text. Read my previous posts – you're uninformed about this matter. Read up on it.

Feel free to tell me why 'Hesperus is Phosphorus' is metaphysically necessary when it is actually false. Or, how anyone can know what "Hesperus" and "Phosphorus" mean to the denizens of a possible world. Or, how a proper name can be universally predicated and remain a proper name.

Read up on it.

First, a rigid designator is used in a certain way in the actual world. Given that meaning, it designates the same object with respect to all possible worlds, regardless of how this term is used, or not used, in those other possible worlds...

Or, how anyone can know what "Hesperus" and "Phosphorus" mean to the denizens of a possible world.

which would have told you that this purported objection is misguided:

Or, how anyone can know what "Hesperus" and "Phosphorus" mean to the denizens of a possible world.

If you read the full objection, you'd see that this is a rhetorical step, not the full objection.

how does Kripke know what "Hesperus" and "Phosphorus" mean in any possible world? As their meaning is conventional, the denizens of each possible world might use them to designate other objects or not use them at all. Kripke has no way of knowing. So, when Kripke says they designate the same object in every possible world in which the object exists, he means he has decided to use the terms in this universal way. So, there is no fact of the matter beyond Kripke choice of naming conventions. Thus, all Kripke has done is define his conclusion into existence: the claim "'Hesperus is Phosphorus' is metaphysically necessary" has no factual basis beyond Kripke's choice of naming conventions.

Your objection seems to rely on analyzing "Hesperus" and "Phosphorus" as definite descriptions rather than proper names.

So, to say that we do not perceive what we are perceiving is an oxymoron and an abuse of language.

Yes, I used "possible" -- not essentially, but to avoid circumlocution. So, here's the same definition restated: "P is possible with respect to a set of facts, S, if P does not contradict the propositions expressing S."

No, a circular definition is no definition, whereas my proposal is an actual definition.

By "reality" we mean what's revealed in reliable experience. So, to say that what we experience is not "real" is an oxymoron

Yes, most of which are modal concepts, hinging on possibility and its correlative, necessity. So, yes, possible worlds talk is circular. I have seen "necessary" defined as true in all possible worlds. Since "necessary" means the contrary is not possible, this is circular.

First, proper names name one, not multiple, individuals. So, to say it's nonsense to say that "Venus" names the same object in every possible world because Venus does not exist in every possible world.

As I pointed out in my critique, your analysis does not consider all possible worlds, only those consistent with certain contingent facts. As you are constraining possibility with contingent facts, the result is only necessary contingently, not metaphysically necessary. For there are possible worlds in which the light in the morning sky has a different source than the light in the evening sky -- even though they both exist, along with a second planet from the sun.

That part of my objection is that words express concepts, so if you want to know what they mean, you have to examine the concepts in terms of the experiences that elicit them. The reason that an empirical discovery is required for the identification is that the concepts are anything but identical.

speaking of worlds as simply "possible" allows one to confuse logical, physical and ontological possibility.

What makes it the case that one thing in one possible world and one thing in another possible world are the same thing?

Let’s say that I’m the eldest of two brothers in the actual world and that there’s a possible world where my parents have two daughters and a possible world where my parents have two sons. Which child, if either, am I in each world? Is it simply a matter of stipulation?

Do we simply say that I’m one or the other (or neither)?

Perhaps in the first possible world it’s me and my brother if we were female? Perhaps in the fourth possible world it’s two different children who happen to look and behave like my brother and I do in the actual world?

Your puzzle stems from the question: what it is that distinguish a possible world where a son is born to your parents that looks and behaves just like you, but isn't you, from a world in which this son is you? Those two scenarios are indeed metaphysically distinct and, what distinguished them precisely, are our ordinary criteria of identity of persons as they are meant to apply in the actual world. It's possible, though, that our criteria of identity of persons aren't fine grained enough to determine whether or not your would have been the same person if the sperm and ovum that your are issued from had combined at a different time, or if the sperm has been a different different one that accidentally shared the very same sequence of nucleotides, etc. That just means that our ordinary concept of a person, and its associated criteria of identity, isn't meant to deal with such unlikely possibilities since there is little pragmatic point in dealing with them.

What makes it the case that one thing in one possible world and one thing in another possible world are the same thing?

It's the exact same sort of thing that makes it the case that "A" and "B" are numerically the same in the actual world: criteria of identity and individuation. Those criteria vary as a function of the sorts of things that are at issue. Planets, persons, sports teams, cell lineages, ocean waves, etc., have different principles of individuation. Sometimes those principles mainly are matters of social convention but they can also be, in part, objects of scientific inquiry.

That's not what I said. I said that perception is not identical to reality, which is what you said.

We don't even have direct access to our own world, so are we able to learn anything about the actual world?

A consistent "set of facts" is one way of articulating what a possible world is so I don't even know what you think you're arguing against at this point.

Naturally "reliable" is doing all the work here, being used to obfuscate the fact that there's no guarantee that perception maps to reality such that we can have an infallible means by which to say some experience is reliable. It's like you've never considered any objection to your views ever.

Necessity is indeed defined as truth in all possible world [of the set of world being quantified over], and yes X being necessary entails that it's negation is not possible. Where is the circularity?

it's nonsense to say that "Venus" names the same object in every possible world because Venus does not exist in every possible world. — Dfpolis

This is exactly what I was talking about, you don't understand this topic.

But that's not how proper names work, they pick out a specific object in the actual world, and the meaning of that name is fixed in modal logic

Obviously "Hesperus=Phosporus" isn't true in the possible worlds where the references to the terms do not exist.

This is all consistent with Kripke's claim that proper names function as rigid designators, and also with his claim that statements of identity of the form "A is B", where "A" and "B" are proper names, are metaphysically necessary.

speaking of worlds as simply "possible" allows one to confuse logical, physical and ontological possibility. — Dfpolis

...distinctions whose advocates can't specify what they mean by them

"P is possible with respect to a set of facts, S, if P does not contradict the propositions expressing S."

A "Venus" in another (possible) world is not our Venus. Therefore, one can only be call both "Venus" by equivocation or by universal predication.

What makes it the case that one thing in one possible world and one thing in another possible world are the same thing?

Then perhaps if we use a simpler example of an inanimate object. In another possible world the Taj Mahal was built using different materials, or at a different location, or with a different architecture. Does that make sense? Is it just a matter of stipulation that we consider them the same thing (or different things) in each possible world?

You believe in an un-acknowledged and unsupported assumption that the physical world that we live in is the "actual", "existent", "physical" and "real" one, in some (unspecified) sense in which the infinitely-many other possibility-worlds aren't.

there's no reasons to claim that they're "real" or "existent", whatever that would mean.

There's no reason to believe that your experience is other than such an abstract logical system.

If you claim that this physical world is more than the setting for the hypothetical logical system that is your experience-story, then in what respect to you think that this physical world is more than that.

Do you believe in unparsimonious brute-facts and unverfiable, unfalsifiable propositions?

Which child, if either, am I in each world? Is it simply a matter of stipulation? Do we simply say that I’m one or the other (or neither)?

It depends on how you define "same". Lewis's suggestion was that "same" doesn't meaningfully apply to someone or something in a different possibility world, It's a different world, necessarily with different (even if identical) things.

This seems an attempt to give possible worlds the same epistemological status as the real world, hence my justification of direct epistemic access.

Facts are actual, not merely possible. Possible worlds might be a consistent set of posits, they are not a consistent set of facts.

Yes, I used "possible" -- not essentially, but to avoid circumlocution. So, here's the same definition restated: "P is possible with respect to a set of facts, S, if P does not contradict the propositions expressing S."

If I didn't consider objections, I wouldn't have said "reliable." Yes, it's doing a lot of work, but that doesn't mean that we can't have true knowledge, where "truth" is understood as adequacy, not as exhaustiveness or infallibility. I've made no claim of infallible human knowledge, so the notion of infallibility is a straw man -- effectively replacing human knowledge with divine omniscience. Primarily, "knowing" names an human activity, so requiring infallibility as you seem to is a bait and switch tactic.

First, it is unnecessary. As we can have no epistemic access to any world but our own, actual world, anything we can learn, we can learn from the real world.

If you can't see that using possible worlds as the ultimate basis for defining possibility is circular, I can't help you.

A "Venus" in another (possible) world is not our Venus. Therefore, one can only be call both "Venus" by equivocation or by universal predication.

But, in my example, the terms are referential via the same types of experiences that give them reference here. Each rigid designator names is appropriate object: There are morning and evening stars and a second planet. It is just that the references are not what you want them to be. You response will define my possible world out of consideration. So, again, the conclusion is based on how you choose to construct a set of possible worlds, not on any observable facts of the matter -- and that is precisely my objection.

We are already speaking of the same individual by stipulation, as it might have been in various scenarios.

It depends on how you define "metaphysically necessary." Can you define it without invoking possible worlds semantics? If not, how can this claim be relevant to reality?

You are under the impression that a rigid designator is a term that could not have meant anything other than what it actually means.

But then that makes the notion of rigid designators philosophically uninteresting. I simply stipulate that in one possible world the Taj Mahal is made of wood and that this glass of water is composed of H2O2, and so I've declared Kripke's claim that water is necessarily H2O to be wrong (and then he's stipulated something else and so declared his claim correct).

If water is H20, it makes no sense to 'stipulate' that a glass of water doe snot hold H20.

And if the Taj Mahal is made of bricks then it makes no sense to stipulate that in a possible world it's made of wood? Or if my name is Michael then it makes no sense to stipulate that in a possible world my name is Andrew?

No, it is perfectly possible to stipulate that an individual may have had some properties other than what it has (being made of something different, or having a different name).

If 'water' means the same as 'H20'

H202, you will note, is not water, but hydrogen peroxide.

Well that's what I'm calling into question. I might counter by saying that the term "water" refers to whatever liquid makes up the Earth's oceans and falls from the clouds as rain and that in some possible world the chemical composition of that liquid is H2O2. That water is H2O is just a contingent fact about the actual world, much like Earth being the third rock from the Sun.

And in my case the individual is "this glass of water" and the counterfactual property is the chemical composition.

Well that's what I'm calling into question. I might counter by saying that the term "water" refers to whatever liquid makes up the Earth's oceans and falls from the clouds as rain and that in some possible world the chemical composition of that liquid is H2O2. That water is H2O is just a contingent fact about the actual world, much like Earth being the third rock from the Sun.

So I'm saying that in one possible world water is hydrogen peroxide.

Then what you are supposing is that the glass of water had instead been a glass of hydrogen peroxide.

In fact, your suggestion doesn't disambiguate between these two possibilities. Of course water is the substance that fills the oceans, etc. Does that mean that the word 'water' means the same as 'the substance that fills the oceans...', etc. No, obviously these do not mean the same, since it is no contradiction to imagine instead that the oceans had been filled with mercury, and in doing so we are imagining a different sate of affairs, a way things could have been, but aren't.

I must confess, to me this sounds like a contradiction, and I do not know how to suppose such a thing – it is like supposing that 2 and 3 make 6, or something like that. If it were hydrogen peroxide, well then, it would be hydrogen peroxide, not water.

Facts are actual, not merely possible

Possible worlds might be a consistent set of posits, they are not a consistent set of facts

It was that, and hence my response regarding how you do not have direct epistemic access. If this access isn't infallible then there's no particularly superior access to your purported knowledge of the actual world over what is possible.

Do you ever stick to what you say or do you change it on a dime when an objection surfaces? Here's what you said before:

Yes, I used "possible" -- not essentially, but to avoid circumlocution. So, here's the same definition restated: "P is possible with respect to a set of facts, S, if P does not contradict the propositions expressing S."

The reason why you required infallibility (whether you acknowledge it or not) is because your initial claim in the OP was this:

First, it is unnecessary. As we can have no epistemic access to any world but our own, actual world, anything we can learn, we can learn from the real world.

My point was that we don't have any better epistemic access to the actual world because of the limitations of perception. Without infallible means of accessing the states of affairs of the actual world, what we perceive to be the case can easily fail to be so. Whatever you mean by "direct access" is completely opaque, and so recourse to reliability here is equally so

Possible worlds as a means to give semantics for possibility is not circular. The only way you could claim that is because the word "possible" is part of the name of the concept.

P is possible if there is at least one world in which P is the case

Possible worlds are not (unless you're David Lewis) being posited as literal other worlds in the same sense as the actual world. It's right there in the name, there's only one actual world. Venus in another possible world is still Venus as it might have been, the individuation conditions return the same object (that's why the names are a rigid designator).

Venus in another possible world is still Venus as it might have been, the individuation conditions return the same object (that's why the names are a rigid designator).

"Second planet" and "morning/evening stars" are not proper names.

the identity holds across worlds (i.e. trans-world identity) because they have the same essential properties which make it Venus.

No, because I'm stipulating that it's the same glass of water. It's just that in the actual world it's H2O and in a possible world it's H2O2.

How is this any different to stipulating that I'm married to the same woman, but that in the actual world she's English and in a possible world she's American?

It's also no contradiction to imagine that scientists have been mistaken (or lying) and that the chemical composition of water in the actual world really is H2O2.

Things can have more than one name. The liquid we drink can either be called "water" (a common name) or "hydrogen peroxide" (a scientific name, referring to its chemical composition), so water and hydrogen peroxide are the same thing, and H2O is something else. This might be false, but it's not a contradiction.

Kripke would readily agree that the statement "Hesperus is Phosphorus" expresses a contingent identity in the case where "Hesperus" and "Phosphorus" are shorthand expressions for definite descriptions that merely happen to have the same reference in the actual world.

Yes, but that's irrelevant. In that case, then 'H202' and 'water' would have meant the same thing, and we made a mistake in thinking that 'H20' and 'water' did. Nothing about Kripke's arguments change. Again, take an example you already agree with.

It's not irrelevant. It's the central point. If we accept that we could be mistaken in thinking that water is H2O then we accept that "water" and "H2O" don't mean the same thing and so that water isn't necessarily H2O. If we accept that water might actually be H2O2 then we are saying that it's possible that water is hydrogen peroxide.

Saying that something is metaphysically possible just is to say that it isn't inconsistent with the way things can be in accordance with the constitutive rules that govern how those things fall under concepts. (For instance, it is a constitutive rule of bishops, in chess, that such pieces only moves legally along diagonals; and it is a constitutive rule of the concept of a human being that it is an animal).

I think it can be shown that if "A" and "B" are meant to function in the way ordinary proper names are used, and they both actually name the same individual, then it is metaphysically necessary that A and B are numerically identical.

But you don't know what you mean by "actual". Or, if you do know what you mean by it, you're keeping it to yourself.

"Fact" is often or usually defined as a relation among things, or as a state-of-affairs.

in what regard, in what manner, do you think this physical world is different from merely the setting for your hypothetical life-experience-story, consisting of a hypothetical logical system such as I've described?

I don't think myself that this is the right way to put it, since if Kripke is right, 'water is H20' just means 'water is water,' and we already knew this trivial proposition a priori. What we learned, if you like, and which is genuinely contingent and a posteriori, is that all along we referred to the same thing with both these words. This is just a fact about linguistic usage (which of course may be a substantive discovery with huge implications, since we resolve what we thought were two things into the true one just by learning this).

It seems to me that Kripke can avoid this problem since although "water" and "H2O", construed as co-referential natural kind terms, have the same reference, they can still be taken to have distinct Fregean senses.

I understand what you are saying, but it is not how I'd define "metaphysically necessary." There is no metaphysical reason a chess bishop can't move like a knight, rook or in any other way. It is merely a convention.

The problem is the common sensical notions won't be able to be used broadly to understand many instances of how we use modal concepts and so it fundamentally doesn't do the job we use possible worlds semantics to accomplish (that is, to give a rigorous account of these ideas)

I suppose it is possible, but he would have to take the senses not to be the sort of descriptive entities that interact with the compositional semantics that they're often taken to be.

What I've never seen, and it's not for want of looking, is what that field of inquiry achieves. It doesn't explain ordinary language, because people don't think in terms of possible worlds.

Yes, but that much is obvious from the fact that words mean things, and what they mean might be opaque to their users. Invoking a dubious notion like Fregean senses is probably not a good idea, unless this obvious fact is all one means by it.

"But you don't know what you mean by "actual". Or, if you do know what you mean by it, you're keeping it to yourself." — Michael Ossipoff


By "actual" I mean operational or able to act.

As mere hypotheticals can't act, they aren't actually facts.

" "Fact" is often or usually defined as a relation among things, or as a state-of-affairs". — Michael Ossipoff


OK. As long as the things and states are actual, I have no problem with this.

"in what regard, in what manner, do you think this physical world is different from merely the setting for your hypothetical life-experience-story, consisting of a hypothetical logical system such as I've described?" — Michael Ossipoff


Because a hypothetical story represents actions and states of affairs that did not occur.

water could not have been anything but H20, since it would have to have been not itself, which is metaphysically impossible

...

What we learned, if you like, and which is genuinely contingent and a posteriori, is that all along we referred to the same thing with both these words.

speaking of worlds as simply "possible" allows one to confuse logical, physical and ontological possibility. — Dfpolis

...distinctions whose advocates can't specify what they mean by them — Michael Ossipoff


I can. I said :

"P is possible with respect to a set of facts, S, if P does not contradict the propositions expressing S." — Dfpolis


Logical possibility means the proposition is consistent with S = the facts we know.

Physical possibility means the proposition is consistent with S = the laws of nature.
Alternately, one may mean the proposition is consistent with S = the laws of nature plus the facts we know about a physical state.

Ontological or metaphysical possibility means the proposition is consistent with S = the nature of being qua being.

”You believe in an un-acknowledged and unsupported assumption that the physical world that we live in is the "actual", "existent", "physical" and "real" one, in some (unspecified) sense in which the infinitely-many other possibility-worlds aren't.” — Michael Ossipoff
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I do not deny the existence of other universes in a multiverse

, or even independently.

I am only saying that, as we are not in dynamic contact with them, they are epistemologically irrelevant.

”there's no reasons to claim that they're [the physical possibility-worlds]"real" or "existent", whatever that would mean.” — Michael Ossipoff
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Anything that can act in any way exists. That is sufficient reason to think that things that act to inform me are real.

”There's no reason to believe that your experience is other than such an abstract logical system.” — Michael Ossipoff
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Of course there is. The things I experience act on me and I am aware of their action on me. Abstract logical systems do not act on me in the same way.

”If you claim that this physical world is more than the setting for the hypothetical logical system that is your experience-story, then in what respect to you think that this physical world is more than that.” — Michael Ossipoff

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Because mere hypotheticals can't act on anything.

”Do you believe in unparsimonious brute-facts and unverfiable, unfalsifiable propositions?” — Michael Ossipoff
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No.

We also refer to the same thing using the words "Donald Trump" and "the 45th President of the United States" but don't say that if Donald Trump wasn't the 45th President of the United States then he wouldn't be himself.

So how do we determine which words are rigid designators – which words refer to the same thing in all possible worlds – and which don't?

Your answer before was that it's just a matter of stipulation. We stipulate that the 46th President in a counterfactual scenario is "the same" Donald Trump who is the actual 45th President, so why can't we stipulate that H2O2 in a counterfactual scenario is "the same" water which is actually H2O? There's this implicit premise that some properties are "essential"1 to a thing's identity and others contingent, but how do we determine which properties are which? You say that the chemical composition of water is an essential property, but perhaps that the material of the Taj Mahal isn't (and so it could have been made of wood, even though when we refer to the Taj Mahal we're referring to a building made of things other than wood)?

It seems to me that possible worlds talk is unnecessary, circular and a source of possible confusion.

First, it is unnecessary. As we can have no epistic access to any world but our own, actual world, anything we can learn, we can learn from the real world.

Right at the beginning, you include assumptions such as "actual world" and "real world". What are these worlds, and where is your justification for their "real" or "actual" existence?

Of course we have access to our own world.

It seems to me that possible worlds talk is unnecessary, circular and a source of possible confusion.

First, it is unnecessary. As we can have no epistic access to any world but our own, actual world, anything we can learn, we can learn from the real world

Second, if the purpose of possible worlds talk is to define the meaning of modal statements, it is circular. If a person does not understand modality, they will not understand the meaning of "possible worlds."

Third, speaking of worlds as simply "possible" allows one to confuse logical, physical and ontological possibility. If one is thinking of a specific other world as possible, it is not clear that what is imagined to be possible will be self-consistent. For example, the calculations undergirding the fine tuning argument show that even small deviations from the real world may have unexpected and possibly unforeseeable consequences. If one is using possible worlds talk to justify Bayesian subjective probabilities, that can't be done without specifying a density of states for which we can have no objective justification.

Thus, possible worlds talk is near the top of the list of philosophical worst practices.

without the jargon, can you say what it would mean to say that this physical world has physical or ontological reality or existence that the hypothetical logical system that I described doesn't have?

Is there a physics experiment that can establish that this physical world is other than a logical system, a system of logical and mathematical relation--as physicist Michael Faraday suggested in 1844?

And if you say that the difference is that this physical world is "actual", then of course I'll ask what you mean by "actual".

or even independently.

I interpret that as referring to other possibility-worlds, logical systems.

As David Lewis suggested, each such physical possibility-world is “actual” for its inhabitants (if it has any). The word “actual” is best defined as an adjective to denote the physical possibility-world in which the speaker resides.

I am only saying that, as we are not in dynamic contact with them, they are epistemologically irrelevant.

…whatever that means. Their “existence” as systems of inter-referring abstract implications is uncontroversial. They’re relevant because we live in one of them.

By your definition, then, hypothetical physical worlds are real, because their constituent things act on eachother

That’s circular. It assumes that your experience-story itself isn’t an abstract logical system.

That hardly can be given as a reason to say that it’s more than a hypothetical story about you and your surroundings’ interaction with you.

Of course they can. They can and do act on other hypotheticals,

”Do you believe in unparsimonious brute-facts and unverfiable, unfalsifiable propositions?” — Michael Ossipoff
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No.

Good. Then you don’t believe in an “objectively existent” (as opposed to hypothetical) physical world whose existence you can’t explain, and whose more-than-hypothetical “reality” and “objective physical existence” you can’t define.

we don't have Objective access, so everything you say about "the world" is necessarily speculative, and will always be so.

So, please justify your claim.

we don't have Objective access, so everything you say about "the world" is necessarily speculative, and will always be so.

The question, then, is whether or not there is an analogous de dicto reading of "water is H2O" such that a counterfactual chemical composition of water is not a contradiction. Given that you've accepted that it's possible that scientists are mistaken in their claim that water is H2O, isn't that an acceptance of such a de dicto reading (else it would be as incoherent as suggesting that we could be mistaken in thinking that Donald Trump is Donald Trump)?

most philosophers do not think that possible worlds are literally real worlds that they inquire about. They think of possible worlds as more akin to logically consistent stories about how things might be.

Some philosophers think that Philosophy involves making "discoveries" about "possible worlds"

I think possible worlds talk is usually intended as talk about logical possibility. I can't remember an article in which that isn't quite clear.

philosophers will use technical language where plain language would do, and this has the effect of making philosophy seem incredibly convoluted to those outside of it, and even leads to errors for those within it. I think possible worlds talk is like this.

The justification is that we don't have Objective access to "the world".

Given that they co-refer or not, they express necessarily true or necessarily false propositions. That you are unaware of which it is, and that this depends on the meaning of the words, is where the feeling of contingency comes from. For it is contingent whether the sentence expresses a necessarily true or necessarily false proposition.

My current definition of possible is:
p is possible with respect to a set of propositions, S, if p does not contradict the propositions of S.

...I do not find it worthy of belief.

It seems to me that this analysis is incomplete. It's surely true that Donald Trump is Donald Trump, no matter what you call him. So, if you read the terms in "Donald is Mr. Trump" formally (as referring to the person), this is simply an instance of the Principle of Identity and so necessarily true. The problem is that is not the only reading. One could read it as "The name 'Donald' refers to the same person as the name 'Mr. Trump.'" In that case, it speaks of a contingent reality, for naming conventions are contingent -- this person could well have another name, like "John Smith" -- or even "David Dennison."

I have no doubt that the two readings express different judgements (intentional existents). Still I have several questions/

Can one distinguish two identically written propositions without reference to the intentional states they express? If one can't, isn't linguistic analysis (formal or informal) derivative on intentional analysis?

Alternately, to what does "proposition" refer, if not to judgements?

I think that the underlying problem here is the assumption that proper names refer to things, rather than to intelligible aspects of reality. "Clark Kent" refers to Jorel's son in his guise of newspaper reporter, not to Jorel's son simpliciter. "Superman" refers to Jorel's son in his guise of the man of steel. By ignoring the aspect under which Jorel's son is designated, the notion of rigid designator distorts the intent of the designating agents.

It is not even true that Jorel's son in the guise of newspaper reporter is Jorel's son in the guise of the man of steel -- even though both designate Jorel's son. In other words, when one learns that Clark Kent is superman, the conditions of designation of each term change. What "Clark Kent" means to the speaker after leaning that Clark Kent is superman is more than what it meant before.

So, while "Clark Kent" is materially the same before and after the revelation, it is formally different. This is seen by examining its scope of application. Before the revelation, the speaker would not apply "Clark Kent" to Jorel's son in the guise of the man of steel, but would after the revelation.

I conclude that the analysis of rigid designation is defective because it it mischaracterizes what proper names refer to. They do not refer to objects, but to intelligible aspects of objects.

However, the cognitive significance of a sentence, i.e. what we're capable of learning from the fact that the sentence expresses a true proposition, outruns its literal semantic content.

So, I do not see how it is possible to say that what we learn "outruns" the literal semantic content, when what we learn (the intentional state elicited) we learn from the literal semantic content. What cpuld you possibly mean by "literal semantic content" other than the intentional state that a literal reading elicits? I

This is like saying that a map with a misprint is not worth anymore than a possible map.

P is possible with respect to a set of facts or propositions, S, if P does not contradict S.

I do think "facts" should be restricted to intelligible reality.

There is no claim of infallibility here. If you think there is, explain how.

The actual world is actual because it acts to inform us. Merely possible worlds do not act, let alone act to inform us. Instead, we inform (or perhaps misinform) them.

First, it is unnecessary. As we can have no epistemic access to any world but our own, actual world, anything we can learn, we can learn from the real world.

We have no access to any possible world. We only have access to our imagination, which can easily be inconsistent. What we know of the actual world cannot "easily fail" if we exercise due diligence. It fails occasionally, but it is usually interpretations and constructs that fail rather than experiential data.

I said that a sensory object's modification of our sensory state is identically our sensory representation of the object. I said that the object informing the subject is identically the subject being informed by the object.

It is the name of the concept because the employment of the tool requires one to construct, or at least recognize, worlds that are possible.

This is inadequate as, unless P is actually true, there is no world in which P is the case. What you need to say is "P is possible if there is at least one possible world in which P is the case" -- and that is circular.

Still, they are not our world, as, if they are different in any way, they are not identical to our actual world. Any world that is not identical to our world is a different world. As each is a different world, each (actual or potential) object in them is a different object from any object in out actual world.

Objects are individuated by the network of relations that contextualize them. If you change one relatum, you change the object's individuation conditions. So, the individuation conditions may not return the same object. E.g. if I am the oldest child in the real world and in the possible world I have an older brother, the individuation condition of being the oldest child will not return me.

Counterfactual propositions can be judged on the basis of real-world potencies. Steve would have enjoyed the trip even if he did not go on it because he is actually disposed to enjoy such trips. If we did not know his relevant dispositions, we could not say whether he enjoyed the trip or not. So, there is no need for possible worlds talk to deal with counterfactuals.

I was thinking of propositions as Fregean propositions: or as ways the world (or aspects of the world) might conceivably be thought to be.

Of course, the very same proposition P can be the content of different sorts attitudes other than judgements, such as the hope that P, the fear that P, the conjecture that P, the antecedent of the conditional judgement that if P then Q, etc.