As with a human, if a quote is given, then a citation must be provided. A human, or an AI, that quotes Pindar without giving a citation that can be readily checked can be ignored. — Banno

Yes. I don't understand exactly why they felt they had to go through all those texts. My point is really that once one realizes that the AI is not a magic fountain of truth, but needs to be treated as sceptically as a human being, one begins to wonder what the point of it is.
There are some things that it can do better than human beings. So let them stick to those tasks.

The physical world seems to have an intelligible structure. If consciousness isn't fundamental in some sense, how can we explain that? — boundless

I'm sorry. I didn't mean to imply that consciousness isn't fundamental in some sense. I was just asking in what sense you think it is fundamental. Obviously, you don't mean in the sense that it is the causal origin of the world.

An explanation that explains why our conceptual models work that isn't reduced to a mere "they work because experience tells us they work". — boundless

So you accept that they do work. But if they work, they provide an explanation - that's what conceptual structures do, isn't it?

This kind of answer means either that:
(1) "it just happens that the physical world has an intelligible structure", i.e. there is no explanation, it's just so.
(2) "intelligbility is illusory". It appears that there the physical world has an intelligible structure but this isn't true. — boundless

I don't understand the first alternative. If the world has an intelligible structure, then there is an explanation why things are the way they are.
As to the second, it happens all the time that we think we have an account of the world and it turns out to be wrong. We just set to work to devise another, better, one.

I do accept both things. However, this doesn't exclude the possibility that some form of consciousness is fundamental as it is suggested by the second 'horn' of the dilemma. — boundless

It depends what you mean by "fundamental". Clearly, consciousness is not the origin of the physical world and does not exist independently of some physical substrate. That suggests that it is the physical world that is fundamental. So what do you mean by "fundamental".

The fact that there is no 'perfect model' that mirrors the way the world isn't enough to say that we get no knowledge of the 'things in themselves'. In other words, my question is: according to all these thinkers is there a reason why our predictive models work? Is it just a 'brute fact'? — boundless

You are right to think that our not knowing all about everything does not mean that we know nothing about anything. However, the reason why our predictive models work is that we test their predictive power. If they fail, we revise the model or abandon it. What more do you want?

nothing in the physical story seems to explain why pain feels the way it does, or why color experience has its distinctive qualitative nature. — Wayfarer

I'm not sure that there is a real question here. It seems to presume that pain might not feel the way it does or colour might have some different qualitative nature. But those possibilities seem like empty gestures to me.

he argues that current forms of physical explanation leave an unresolved conceptual gap between objective accounts and subjective experience, a gap that cannot be closed simply by adding more neuroscientific detail — Wayfarer

That's true. However, it seems to me to follow that the metaphor of the gap that can't be closed does not work. It assumes that the two sides of the gap are, somehow, in the same category or commensurable. But physics is designed to exclude anything that doesn't fit its methodology. Nothing wrong with that, until you start claiming that the physical world is the only real world.

As I said before, I see the physical world as an artificial construct, the real world being made up of consciousness and mind, which acts out certain things in the artificial world for some reason, or other. — Punshhh

There's no doubt that the physical world, as treated in physics, is an artificial construct, so I agree that it has no special claim to be the real world. However, I see consciousness and mind, as conceived here, as an off-shoot of that construct. The real world has both as natural inhabitants and co-existents. In the real world, physics needs conscious, mindful people and conscious, mindful people need the physical world.

Folk treat this as an "authority", but of course any authority here would be granted by the participants, not presumed. That is, if you disagree with the AI's response, then you could openly ask it for an alternate response, to ground your objection. — Banno

I heard an account from an academic that told of an AI, in response to a question, providing a factually wrong answer about Pindar; when questioned, it doubled down on its mistake by providing quotations to back up its claim. A long search through a lot of actual text in an actual library eventually proved that it was wrong. It had written the quotations itself. Many hallucinations will not be subjected to that level of examination. What earthly use is a machine like that? One might as well ask one's next-door neighbour.

Using AI in this context can be frustrating but it ultimately saves time and avoids tedium. It's also a very direct and fast way of understanding the ways that LLMs get things wrong generally. — Jamal

Nobody could quarrel with saving time and avoiding tedium. Your suggestions all seem sensible to me. If people don't find them useful, I'm sure they'll let you know.
But I'm very concerned about the way that LLMs get things wrong. Please can we think carefully about ways to trap harmful errors?

There is the SOA (snow is white)
There is also the SOA (snow, being white, is well known)
There is the problem of disconnecting the world from the thought of the world, when we only know the world through our thoughts.
Being known is a thought, but then being white is also a thought. — RussellA

I'm really quite confused. I lazily though that that-clauses would work - after all, thinking that snow is white and the fact that snow is white are perfection in order grammatically. But the state of affairs that snow is white doesn't sound right. Your way of doing is comprehensible, but not standard English. Which doesn't mean it's wrong. But there must be a standard English way of doing it. On the other hand this gerund business is very curious, yet seems to make grammatical sense. I had thought vaguely that "the state of affairs that snow is white was all one needed.
Then there's the business about states of affairs obtaining rather than existing. My intuition tells me that there is no need for that, but isn't certain.

Have a look at the relevant part of the article:-
SEP - States of affairs 1.1

We may have the concept of a possible world where there is the State of Affairs (snow is white), and we may also have the concept of a possible world where there is the State of Affairs (snow is black). — RussellA

I looked up the SEP - States of Affairs
In section 1.1, I discovered that states of affairs are in fact expressed by gerund clauses, as in "Charlie’s eloping with Ginger was surprising" or "Mary’s divorcing Charlie caused Charlie’s demise" or "Kareem Abdul-Jabbar’s being more than seven feet tall is well-known". I was somewhat relieved that they are related to facts and thoughts.
I think that this is all a philosophical mare's nest around a grammatical device in language. I don't say there is nothing here, and I'm prepared to be convinced.

he (sc. Wittgenstein) uses it (sc. the shadow metaphor)as a stepping stone towards dropping meaning in favour of use. — Banno

Since it doesn't occur in the Phil. Inv., one thinks it must be some sort of stepping stone. It didn't make the cut. But I think that's a pity - though no doubt he had his reasons. His discussion of pictures and sentences show traces of the TLP with its similarity of structure. Perhaps that's why it didn't survive into the PI.
He articulates meaning as use on pg. 4 of the Blue Book, but doesn't mention shadows until pg. 36. So whatever kind of step it was/is, he had meaning as use when he made it.

"Caesar is a General" is true IFF Caesar is in the extension of "...is General". — Banno

I'm a bit bothered about this. Caesar was not always a General, so would ("Caesar is not a General" is true IFF Caesar is not in the extension of General) also count as timelessly true?
It is clear that there is no contradiction here. Yet contradiction seems only to require that p and not-p are never true of the same object simultaneously. We need time to apply that law, but timelessness doesn't have time.
It's just that necessary/analytic/a priori truths are clearly timelessly true. Both hypotheses are true, but it is the formula as a whole (p IFF p is true) that is timelessly true, not the constituent sentences.

In giving up the dualism of scheme and world, we do not give up the world, but re-establish unmediated touch with the familiar objects whose antics make our sentences and opinions true or false. — On the very idea of a conceptual schema

Yes. One remembers that sentence. I'm still a bit hesitant, because I think that the distinction is useful, even if it is not always apposite.

But I cannot understand that if in a possible world there is no apple, there still is the apple’s haecceity — RussellA

Is it possible that the haecceity in question is the haecceity of the possible apple?
Really, there is no making sense of this. I know it is not proper philosophy. Some poets make fun of similar issues.

Yesterday, upon the stair,
I met a man who wasn't there
He wasn't there again today
I wish, I wish he'd go away...
etc. — Hughes Mearns

Or there's "The Railroad Station" by Wilawa Szymborska.

Yep. There is something quite odd about such ghost-apples. — Banno

Wittgenstein makes a major feature of what he calls "shadow" objects in the Blue and Brown books.

The next step we are inclined to take is to think that as the object of our thought isn't the fact it is a shadow of the fact. There are different names for this shadow, e.g. "proposition", "sense of the sentence". — Page 32 Blue Book

He explores the idea in some detail.

But the actual world can only exist at one moment in time. — RussellA

The idea that only the present exists is really very odd. "Present" only has meaning in the context of "Past" and "Future". They all exist in the fashion that's appropriate to them. They form a conceptual system, and claiming that only one of them exists is like forgetting that "North" only has meaning in the context of "South" (and "East" and "West").

We might posit two more states of affairs, D and E, to account for these changes, but then we have changes between A and D, D and C, C and E, and E and B, requiring more states of affairs. And so on. — Metaphysician Undercover

That's the argument. What's your solution? To posit that all change takes place instantaneously between states of affairs? That's absurd. It is clear that most changes take place continuously over a period of time. Look around you.

And it's not that simple. If we redefine "state of affairs" as you suggest, such that 'state of affairs" covers all of reality, then all you have done is produced a false description of reality. — Metaphysician Undercover

How do you know that reality is different from my version? Because of that argument? It is not a description of reality, but a reductio ad absurdum of a certain way of thinking about reality.
I did not say that "state of affairs" covers all of reality. I did allow that there are some events that do not fit in to that category.

This is the principal reason for Aristotle's duality of matter and form in his physics. When one state of affairs changes to another, the form or formula changes, but matter provides for the underlying continuity between the two. — Metaphysician Undercover

Exactly. So there is no need to insist that all change occurs between states of affairs. I don't agree with his metaphysics, but it does solve the problem he was facing.

What other ways? Do you mean to define words so that they reflect the way that you want reality to be, rather than the way that it is? That's not very good ontology. — Metaphysician Undercover

I like to define words so that they do not produce absurdities.

The reason is the argument presented by Aristotle. Suppose at some time we have state of affairs A, and at a later time state of affairs B. Since these two are different we can conclude that change has occurred in the time between A and B. As philosophers we desire to know and understand this change. We might explain the change with a third, distinct state of affairs, C, which occurred between A and B, but then we have a change which occurred between A and C, and between C and B. We might posit two more states of affairs, D and E, to account for these changes, but then we have changes between A and D, D and C, C and E, and E and B, requiring more states of affairs. And so on. — Metaphysician Undercover

So it does depend on the definition of "state of affairs". Aristotle's argument is indeed a good reason for changing that definition, to allow that states of affairs can comprise change. Problem solved!

This is the principal reason for Aristotle's duality of matter and form in his physics. When one state of affairs changes to another, the form or formula changes, but matter provides for the underlying continuity between the two. — Metaphysician Undercover

Yes, I knew that was why Aristotle constructed his system. But I don't think it would be helpful to adopt it now that we have other ways of explaining it.

Right, so what I am talking about is something which cannot be placed in that category. The name "state of affairs" cannot be used to refer to this. — Metaphysician Undercover

I thought so. Can you give me a reason for restricting the term in that way?

EDIT
On reflection, there is a bit more that I can say.

I have no doubt that change can be accommodated as a "state of affairs".
@Banno has already given an example, I offer "The plane is flying from London to Edinburgh" is clearly a state of affairs. But it is a process which will not change (much) as long as it is flying. That is, it is a continuous process, which occupies time.
We can also easily accommodate changes in the process. The plane may fly faster or slower, lower or higher, but all these changes are easily accommodate as states of affairs.
"The plane is taking off" also seems like a state of affairs. But it is accelerating, which means that its speed is changing. In this case, the speed is not just changing but the rate of change is changing. )The place accelerates faster as it travels down the runway.
But none of that presents a problem. What might present a problem is the fact that to speak of accelerating involves a concept of speed at an instant, But speed is defined as distance covered in a period of time, If the period of time is infinitely close to zero, it seems problematic. But the calculations work perfectly well, so I don't see that as a problem either.
But there is a problem here. If the plane started moving at 1:00, are the wheels turning at 1:00? In which case, it has already started at 1:00. Or are we to say that the wheels are stationary at 1:00? In which case, the plane has not yet started moving at 1:00. We may end up saying that the wheels were moving at infinite velocity at the moment of starting.
In other words, limits and boundaries do present problems and we may have difficulty saying what the state of affairs is at 1:00. This is not really a problem about states of affairs, but about boundaries and limiis. We need to recognize that they belong to neither of the states of affairs that exist on either side of them; these are in a different category and do not occupy space or time.
I think that this is the problem you have in mind when you talk of change between states of affairs.. But, I hope you can see that the problem is not about all changes, particularly not about changes that are processes and occupy time. It is about a certain kind of change, which is a boundary or limit. Nor is it a problem that affects just talk of "states of affairs". The same problem occurs whenever those changes occur and would face us whatever notation we decide to use.

If you reject the sound logic, and simply refuse to accept that there is any part of empirical reality which cannot be describe as states of affairs, then you are in denial. — Metaphysician Undercover

When we reach the limits of what "states of affairs" can do for us, and there is still more reality to describe, we must devise a new way to speak about it. — Metaphysician Undercover

It all depends on how you define "state of affairs". "Description" is simply a name for specific kinds of language, mostly those that are true or false. "State of affairs" is simply a name for what the description is a description of. It has very little content, like the word "thing".
There are also metaphorical descriptions, which are more complicated - but are often the engine that generates new kinds of description. When we have invented new kinds of description, "state of affairs" is extended to include those new kinds of description.
In other words "state of affairs" is just a correlative to "description", and is no more limited than "description".
You seem to have a more limited idea of what a state of affairs is. But it is just a question of definition, not of the nature of reality.

In both cases we are referring to something that does not exist. — RussellA

You keep saying that. But I don't understand what it is that we are referring to. What's worse is that you are saying on one hand that this object must exist and that it doesn't.

We can talk about Sherlock Holmes who does not exist, and Meinong’s logic can deal with non-existent objects, such as round-squares — RussellA

In a sense, both halves are true. The difficulty is that Meinong, IMO, doesn't explain anything, but simply assigns names (labels) to the problems. What we need is a way of seeing through the problems so that we can understand that they are illusions created by our misunderstanding of language. That's what the logical analysis is intended to do.

Thank you.

In possible world, say W34, there are no apples at all. Then the proposition “there is no apple on the table” is true.
What would the logic statement be for this possible world W34? — RussellA

I'm pretty sure that it is "In W34(¬∃x(P(x)∧Q(x)))". But I'm no expert. Perhaps @Banno will comment.

To say “there is no apple on the table” is no different to saying “there is no apple in the set”.
In both cases we are referring to something that does not exist. — RussellA

I don't understand you. The table exists, and the set exists. We are not referring to any specific apple and not asserting either that apples in general exist or that they don't.

The proposition "There is something that is an apple and this something is not on the table" can be written as ∃x(P(x)∧¬Q(x)) where P(x) means "x is an apple" and Q(x) means "x is on the table" — RussellA

That might be true, when, for example, there is only one apple around or when I mean that the apple I'm holding in my hand. But ¬∃x(P(x)∧Q(x)) identifies a different state of affairs, which does not refer to any apples.

EDIT
I'm not saying that there is no problem about referring to non-existent objects. I am saying that this isn't it.

I suggest that it's simpler to semantically equate, “there is no apple on the table” with the fact that apples are not in the set of objects on the table. — Relativist

Thank you. That's much better.

In Ordinary language, when we say “there is no apple on the table”, we mean that the apple does not exist. — RussellA

Do you mean that the apple that might be on the table does not exist? Clearly, there is not, in this world, any apple that might be on the table. That apple only exists in the possible world in which there's an apple on the table. If there are many apples that might be on the table, each apple will exist in a different possible world.

In ordinary language, if “there is no apple on the table” is true, then there is no apple. The proposition is referring to something that is non-existent. This seems like a puzzle. — RussellA

No, this seems like a muddle. "There is no apple" needs a context to be meaningful.

Yes, in modal logic, if in W3 the apple exists but does not obtain, and in W6 the apple exists but does not obtain, is this the same apple or a different apple even though it is identical. — RussellA

I don't know which apple you are referring to as "the apple". Are you using "does not obtain" to mean "does not exist in the actual world"? In general, IMO, the identity or difference of objects across different worlds depends on the specific details of the case. One cannot generalize.

This is the problem that modal logic solves. The apple exists even if it does not obtain. If it exists then it can be included within modal equations. — RussellA

Yes, but you have to specify in which world these apples exist.

So a relativist has a conundrum -- how to make an argument against foundationalism without making a universal or truth-based claim? — L'éléphant

Not necessarily.
It is often argued that any foundationalism leads inevitably to an infinite regress - what are the foundations of the foundations?
Or it might be simply based on a critique of the foundationalist's argument. (Somewhat as the arguments against the existence of God are often based on a critique of the arguments for God's existence.)

Foundationalism, on the other hand, is, at its core, an epistemic principle whose theory is based on axioms and justification. — L'éléphant

If the epistemic principle is truth-based, it will not justify any moral principles. If it is value-based, it will beg the question.
Axioms are a weak foundation for any assertion. Euclid's axioms allow him to demonstrate geometrical truths, but only if they are true. Different axioms, different "truths". To put it another Euclid's theorems are only true relative to his axioms. Or do you think that there are some self-evidently true moral axioms?

However the penchant for a modal ontological argument gives me pause. — Banno

I looked this up. I see what you mean. His argument feels like a construction for a pre-determined outcome - as does his theodicy. Perhaps I'm being too black-and-white. Most likely, with Christians who indulge in philosophy, there is influence both ways.

All this by way of mostly agreeing with you. Including the suspicion that Plantinga is misled by his faith. — Banno

From what I've seen, it does seem very likely that Plantinga thinks that there is a connection between his philosophy and his faith. But I'm pretty sure that there are Christians who accept his faith but not his philosophy, I suspect it is not really the faith that is misleading him, but good old-fashioned philosophical mistakes.

Possibility 3 - the apple is not on the table
Possibility 6 - the apple is not on the table
Possibility 9 - the apple is on the table
Possibility 12 - the apple is on the table — RussellA

I don't quite understand this. 3 and 6 appear to be identical; so do 9 and 12. So we are considering two possibilities.
"It is possible that the apple is not on the table" and "It is possible that the apple is on the table".
Both these sentences presuppose that there is some specific apple in question. Normally, one would work out which one from the context. But here, there is no context, so no clear interpretation of the sentences is available.
As they stand, the first sentence means "There is no apple on the table" which doesn't refer to anything non-existent and "There is an apple on the table", which refers to the apple on the table, which does exist.
So I don't see your problem.

The possible worlds could supply an appropriate context. But whether the apple in W3 is the same apple as the apple in W6 or the apple in W9 is the same as the apple in W12, - or perhaps the same apple is in question in all four worlds - is a question of trans-world identity. That's an awkward question, but at least we have a context that supplies an apple to be referred to. But I wouldn't be dogmatic about how all that works.

The general problem of non-existent objects has two facets. The only such objects that we can talk about are objects like "the present king of France" or "Pegasus" or "Clark Kent a.k.a. Superman". These are all defined in a context which gives the terms some meaning, while at the same time stipulating that their existence is confined to those specific contexts and excluded from what we are pleased to call the real world. It requires a certain mental gymnastics, but people seem to manage it, on the whole. Without some such conceptual device, I don't see how one can say anything at all about non-existent objects. They have to exist in some sense if we are to talk about them at all.

Plantanga proposed “haecceity” to account for this uniqueness of entities. — RussellA

So far as I can see, "haecceity" has no meaning beyond "the property that accounts for the uniqueness of entities". It is just a label for the problem.
Since non-existent objects don't exist, they can't possess haeccity". So it is doesn't help with non-existent objects. .

How do you address the ontology of the hypothetical apple? .... — frank

"I might have had an apple for breakfast" (a) is puzzling when we ask which apple I might have had for breakfast, and then we wonder about the ontology of the hypothertical apple as if it were a kind of apple. We understand "I might have had that apple in the bowl" (b) for breakfast without positing an hypotherical apple; we even understand "I might have had one of the apples in the bowl for breakfast" (c) without positing hypothetical apples. The puzzle lies entirely in the difference between (a) and (b) or (c). (a) is perfectly comprehensible until you ask the follow-up question which apple you might have had. The question doesn't have the context that would enable an answer. Brutally, there's no such thing as a hypothetical apple; there are only hypotheses about apples.

Heicceity is an historic term, going back to John Duns Scotus in the 13th C, who proposed that although an object is no more than its set of properties, haecceity makes the object unique and different to any other object. — RussellA

We can ask whether this object is red or heavy or... We then notice that there is nothing to prevent something else having just the same properties. After all, a property is inherently something that can occur more than once. There is no guarantee that the same bundle will not occur again. But it is no help to posit yet another property and attributing to that property the magical capacity to be uniquely found in that object. It just makes another puzzle. In specific cases and contexts, we distinguish objects from each other in specific cases and contexts.

It seems that the caravan has moved on while I was away. But thank you both for making me think through what I was saying.

If Aristotle, and perhaps Homer, never actually existed, yet Aristotle and Homer are rigid designators, then what is Aristotle and Homer actually designating. — RussellA

Well, Homer is the author of the Iliad and the Odyssey. So presumable "Homer" designates that person whoever he may be. The difficulty is not just that someone else wrote those epics, but that they were a) not written down (until long after they were created) and b) not created by a single author. The poems were part of an oral tradition in which each poet created their own version(s), so b) our ideas of authorship and texts do not apply in that culture. I wouldn't press this as any kind on knock-down argument here. It's just an interesting conundrum.
`

That would be very interesting if you could explain a reasonable difference between these two. The former would be an actual predication, the latter would be an imaginary predication. Is that what you're saying? — Metaphysician Undercover

It's easier than that. Existence is not a predicate. I'm not quite sure whether being imaginary counts as a predicate, but there's no doubt that "imaginary" excludes "exists". What does exist (in our world) is the account that people give of what they have imagined. Whatever has been imagined would then count as a possible object, and so existent in another world, not this one. Yes?

Perhaps we don't need a theory about the nature of possible worlds in order to use modal logic to regiment modal discourse. An open rather than a close approach. — Banno

It so happens that I think that many, though not necessarily all, questions about the nature of things are ill-formed, because what is meant by nature is not well-defined in the relevant context. So I am extremely comfortable with that approach.

However, Kripke argues for necessary a posteriori knowledge, that some truths can only be known through empirical observation. Therefore, even though my knowledge of Aristotle may be totally false, when I use the name Aristotle, it is still a rigid designator because the name still refers to the actual Aristotle. — RussellA

So is the name "Homer" a rigid designator in this case?
Wikipedia - Homer,

This conflates possibility with potential. It's true that, given what occurred, the counterfactual is not possible. But the question is whether or not what occurred was necessary or contingent. — Relativist

Well, my question is how to tell the difference between necessary and contingent. It seems that any contingent statement becomes necessary if the relevant conditions hold. I don't see that distinction as particularly interesting.

That you do not have at hand a definite description of Aristotle does not make your reference fail. The person you are mistaken about is Aristotle... the reference still works, even in near-complete ignorance. Indeed, there are examples in the literature of reference working in complete ignorance. — Banno

I'll have a look at Donnellan and see. There's something going on here that I haven't pinned down.

“Learning” smuggles in a representational picture: as if what is transmitted along the chain is a mental grasp of an object. That’s exactly the picture Wittgenstein is trying to loosen. On his later view, what is transmitted is not knowledge of a bearer but participation in a practice. Hence my suggestion. — Banno

Oh dear! That was so far from my intention that I lost sight of the possibility. I thought everything that I said emphasized knowing how to use the term.

I probably should not have mentioned the fiction argument at present. It works by rejecting maximal consistency, which has it's own consequences. They may be treated as partial, consistent worlds. Poor pedagogy on my part. But it's were we might go.... — Banno

It wasn't your fault. I brought the topic up, in my innocence. But I think the issue here is what the limits of possibility are and the complication is that there are different limits at different levels. For example, it is not physically possible that the sun does not rise in the morning, but it is logically possible. Whether it is possible to imagine such an event is different again.

Yes, but the same could be said for any so-called "possible" world one entertains with the semantics. If I had my way, we'd distinguish between fictional and possible worlds. — Relativist

I don't disagree. I made the connection because I thought the analogy/similarity between fictional worlds and possible worlds made it easier to understand the latter. I underestimated the difference.

I agree that there is this difference between a fictional world and a possible world, that the possible world might or might not exist - become actual, if you will...
— Ludwig V
Only if it pertains to the future, and is consistent with the history of the world up to the present, and everything else we know about the world. — Relativist

Well, "it is possible" does pertain to the future, because it is in the future that the possibility resolves. If it is possible that I win the race, I win or lose the race in the future. Past possibilities - "it was possible" - are, by implication resolved and I have already won or lost. I do think that, like probabilities, the future is part of the concept.

However, when entertaining counterfactuals about the past or present, the implication is that this counterfactual world could possibly have happened. But could it? This is analyzable and debatable. It's a very different debate if we're simply examining the coherency of a fictional world. — Relativist

It is tempting to agree that counter-factual is a possibility. But the game of alternative history suggests that a counterfactual does not contemplate a possibility, but an event, whether it is possible or not. "How would things be now if Hitler had won the war?" Since he did not, it is not possible that he did. Yet somehow we can contemplate that eventuality and build a coherent story from it.

That's the role of w₀. You answered your own question, I think. — Banno

I'm glad you agree with my answer. It gives me confidence that I'm not thinking rubbish.

I've again got "A nice derangement of epitaphs" in the back of my mind here. A reference is successful if the enterprise in which it is involved is a success. — Banno

I wouldn't quarrel with that. I wish I could get hold of the article, but the only source I found wants £55 for a copy.

I am assuming that each possible world will have a similar recursion and therefore be capable as functioning as a world of origin. Yes?
— Ludwig V
Yes. — Banno

So each world serves as the origin of its transworld identifications. Which world is the origin depends on which world we are in. Each world is the actual world in that world.

This is a different point, further complicating the issue; that since in the actual world Tolkien developed Frodo as a fictional character, we might decide that Frodo is necessarily a fiction - a fiction in any possible world in which he occurred. What this would mean is that were we to come across a small hairy man with nine fingers who was a friend to the elves and wizards, that would not be Frodo, because he is actual and Frodo is a fiction. — Banno

I think that works for this case. But fictions are a varied bunch, so a story about a real or possible person in our world might well count as a possibility and what you say here wouldn't apply. What about stories that mix real and fictional characters and/or places?

What you learned is irrelevant. You heard someone use the word Aristotle, and you started to use the word; and crucially, you would be talking about Aristotle even if what you think you know about him were completely wrong. — Banno

H'm. I'm working this out as I go. You have a point. But I'm inclined to say that other people would take me to be talking about Aristotle. I, on the other hand, don't know what I'm talking about. But there is an objectivity here. The interpretation of people in general determines what is the case, so it is not wrong to say my deviant use is wrong.

(Remember - what preserves the causal chain is people using the tag.)
— Ludwig V
Yes! And that alone! — Banno

But surely the causal chain is a chain of people learning to use Aristotle in that way. I agree that one person does not determine anything.

If you overheard the bloke on the TV say that Aristotle Taught Alexander, and assumed he meant that Aristotle taught Alexander Graham Bell, and that was all you knew about Aristotle, you would be mistaken, and importantly, you would be mistaken about Aristotle. The reference works despite all you know about Aristotle being wrong. — Banno

Yes. But the causal chain is a chain of people learning to refer to Aristotle correctly. Isn't it? What else could it be?

1 - For me, the name Aristotle is a tag to what I learnt about Aristotle.
3 - There is a reality to Aristotle in 350 BCE, even though I may not know what it is. — RussellA

1. What you learnt about Aristotle enables you to refer to Aristotle - to use the tag. (Remember - what preserves the causal chain is people using the tag.)
3. Yes. It is that reality that enables Kripke to pass off "rigid designation" as a real thing. It is what enables other people to think of Aristotle even when a parrot or speaking machine says Aristotle. Nonetheless, the link is established by the continuous use of the name by people who understand it.

iii) “There are possible concrete worlds other than ours” presupposes that there are other concrete worlds
iv) “Possibly there are concrete worlds other than ours” does not presuppose that there are other concrete worlds — RussellA

That's perfectly clear. Thank you.

We produce a fictional idea, a possibility, then to make it fit within the possible worlds semantics, we assign concrete existence to it. This is unacceptable, to arbitrarily, or for that stated purpose, assign concrete existence to something completely imaginary. — Metaphysician Undercover

No, we don't have to assign existence to it. All we have to do is to imagine or suppose that it exists.

There is no logical problem with imagining something as being actual and concrete. — RussellA

Quite so.

"May not a paranoid's delusions of persecution be frighteningly coherent? May not a patient's faith that a mere placebo is a wonder drug be therapeutically useful? Russell was quick to claim in opposition to Joachim that multiple systems of beliefs may be internally consistent, though incompatible with each other. Nietzsche had already suggested well before James that false beliefs may be not merely useful but indispensable for life. "
--Truth -PRINCETON FOUNDATIONS OF CONTEMPORARY PHILOSOPHY ; Burgess & Burgess, pg 3 — Relativist

I wouldn't disagree with any of that or with the familiar point that none of those uses or benefits is a substitute for truth.

The book establishes a fiction. We could examine this fictional world for coherence, and draw valid inferences if (and only if) it is, but the inferences are all qualified by, "within Tolkien's fictional world...". But no unqualified objective truths can be inferred. — Relativist

That's true so far as it goes. But the existence of the book does establish that there is a fictional world in which.....

And critically- nothing here establishes the hobbit world (in toto) as anything more than a fiction, so calling it a "possible world" is misleading. — Relativist

I agree that there is this difference between a fictional world and a possible world, that the possible world might or might not exist - become actual, if you will, but we know that the events in LOTR could not possibly take place. On the other hand, many stories seem entirely possible - and there are docudramas. Characterizing the verisimilitude that is required to persuade us to suspend our disbelief is not easy. Aristotle, if I remember right, uses a word that is translated as "plausible". Is that better?

Not within the logic. We might do that when we give the edifice an interpretation. — Banno

Oh, yes. I'm happy to respect the distinction. I may not always understand it.

So, if there exists possible worlds, are they all existing together as a collection in some world that contains them all? — QuixoticAgnostic

That's not quite what my analogy of the bookshelf of possible worlds proposed. It is the descriptions of all the possible worlds that exist in our world. What the descriptions describe or refer to is something else. Where they exist, in my opinion, is not a question that has an answer. Compare this question with "What happened before the Big Bang? Where did the Big Bang happen?" It is not possible to define a framework that could enable a normal answer to be given. Similarly, but differently, those questions about Middle Earth are unanswerable. Fiction is a curious and paradoxical business. It works very hard at what we might call verisimilitude while at the same time denying that anything in them is real - except, confusingly, those elements of reality the authors insert into the fiction. Our ability to immerse ourselves in these worlds ought to be astonishing, but is too much part of our everyday lives to be noticed as such. It's no wonder that sometimes people don't know where the boundaries are.

Kripke’s solution bypasses any metaphysical problems as to the essence of Aristotle. The name Aristotle is just a tag to something else, and in this case that something baptised Aristotle. — RussellA

Yes and no. A name is not like a tag, though a tag is, in some ways, very like a name. Both serve us as ways of identifying things and people. But what maintains the connection between name and named is the use of both. It is handed down from one person to another, and that is the connection Kripke identifies. But this means that anyone using the name needs to know what and who Aristotle is, so it is very odd to say that the link between name and named exists even if no-one know about it. It seems plausible because we - the audience - know what we need to know.

Aristotle is necessarily Aristotle even if no one knows it. An instance of necessary a posteriori. — RussellA

I find that remark almost impossible to understand. Such understanding as I have of it rests on my knowledge of who and what Aristotle is.

Anyway, note that the name of that individual in w₀ - Aristotle - is used as a rigid designator in order to stipulate the very same individual in a different possible world in which he is called Barry. See how the designation w₀ functions in this game? It's the from where that the rigid designation is fixed. — Banno

Yes, I get that. But that gives w₀ a special status that differentiates it from all the other possible worlds. I suppose, though, that one could point out that for someone in that different possible world in which he is called Barry would make the same claim, with the names reversed. So who a name refers to depends on what world one posits as the world of origin. My question is, whether the system can work without positing some world as the world of origin.

I hope we might leave the theory of reference to one side - we have enough distractions. But I might just suggest that there does not appear to be any reason to think there must be One True Account of reference - there may be many ways in which we can use a proper name. What is salient is that Kripke and Donnellan showed that proper names do not always and only refer in virtue of an attached definite description. — Banno

I wouldn't argue with any of that. The idea that there may not be One True Account of reference seems very plausible to me.

The claim that “there is a possible world in which hobbits exist” amounts to nothing more than the claim that the predicate hobbit is satisfied by at least one object in the domain of some world. No commitment follows to hobbits existing outside that domain, nor to their being actual, concrete, or real in any further sense. — Banno

Quite so.

It's a neat point to put pressure on. The simple answer is that the possible worlds are in w₀, the actual world. But all this means is that it is we, in this world, who are talking about them and quantifying them, and they are in our domain of discourse.
What looks a bit paradoxical is actually a recursion. That recursion enters when we describe all possible worlds from the standpoint of a particular world — that’s the “loop” that looks tricky, but it isn’t a real contradiction. — Banno

I am assuming that each possible world will have a similar recursion and therefore be capable as functioning as a world of origin. Yes?

There is a difference between saying “there are possible concrete worlds other than ours” and “possibly there are concrete worlds other than ours.” — RussellA

I've puzzled about this a great deal. Can you explain the difference to me?

Another way to ask this: what is it that establishes the truth of the statement, "there is a possible world in which Hobbits, Trolls and Orcs exist" — Relativist

Why isn't a copy of the book(s) enough?

Ludwig V is right to point out that whenever we speak of "owning" somebody or somebody's life, unless we do mean slavery, there is something odd about this sort of speech. — Gregory of the Beard of Ockham

There is indeed something odd. I think there are two aspects to it. The first is fairly straightforward "A owns B" asserts that A has the means to control B and is not inhibited from exercising it. The second plays of the implicit reference to slavery and suggests that B is a lesser person as a result. It is like calling a human being an animal. In one way, it is a fact, but in another, it is an insult.

It is not univocal with "owning" a car, a house, a picture, or even a pet. — Gregory of the Beard of Ockham

I agree. And it is even less univocal with "I own my own life". But perhaps the point here is to assert one's right to decide whether and when I have the right to end my own life. The bad news is that it is not an argument.
Perhaps, in some contexts, the relevant part of the metaphor is the assertion that I do not own my own life. The implicit claim is that there are some decisions about my own life that I do not have the right to make. This may well be true, in the sense that we all have responsibilities to others, in one way or another. But it does not follow that there may be circumstances when those responsibilities fall away, as when I am no longer able to meet them.

For my own part, the possiblism/actualism debate is much ado about very little. — Banno

I find it keeps slipping from my grasp.

What we don't have here is any inconsistency... — Banno

It wasn't that I saw an inconsistency, it was just that I didn't see how it fitted together. However, doesn't the idea that we can choose which world is actual conflict with the definition of "truth simipliter" as "true in w₀"? Or, better, if we choose to locate the world in which we construct the possible worlds in w₀, (which isn't a problem in itself) doesn't that conflict with the idea that we find ourselves in that world, and do not choose it. That's why I've been trying to locate that move in a different context from the choices we can make about other possible worlds. Don't we need to mark a distinction between that world and any world we choose to treat as actual for purposes of logical analysis? just labelling it metaphysical doesn't explain anything unless we have a good definition of "metaphysical".

Sea water >96% H2O unsafe to drink
Purified water >99% H2O safe to drink but long term use may deplete essential minerals
Purified heavy water >99% D2O ok to drink in very small quantities but very hazardous in larger amounts
All use the term “water” but there is no common essence between them. — Richard B

I don't have a problem with this. It all goes back to the concept of a game as a network of common elements - more like a rope (which has no thread running through its entire length, but is composed of shorter threads that overlap and interlock) than a filament (like a fishing line) which isn't made up of strands. But it's not an actual argument, more of a challenge. On the other hand, so far as I know, no-one has yet risen to it, so it is very persuasive. Kripke is the exception here. No doubt he would sweep it under some carpet. But that doesn't mean it is not true.

Contingent
A modal variability across worlds, something is contingent if it exists in some, but not all, possible worlds. And similarly, sentences are contingent if ◇P ^ ◇~P. If it exists in all possible worlds it is necessary. If it doesn't exist in any world, it is impossible. — Banno

So what do you do with Kripke's Aristotle that necessarily names Aristotle in all worlds in which Aristotle exists? (Is it really impossible that Aristotle could not have had some other name, if he was born at the right time of the right parents and did all the right things?)

So, if there exists possible worlds, are they all existing together as a collection in some world that contains them all? — QuixoticAgnostic

Yeah, and it doesn't help when folk throw "concrete" into the mix... — Banno

Oh, very good. Concrete is the mix.

Seems to me that the answer is to understand "actual" as an indexical. It's our world. It will change as "our" changes. — Banno

That's a good idea.

But I'm bothered by the facts a) that the actual world is the one in which we are constructing the possible worlds and the point of view from which we are surveying them and identifying which world we wish to treat as actual and b) that we do not choose that world - we are lumbered with it - even thrown into it.

I think this is what you mean when you say that the issue is metaphysical. However we classify it, it looks as if we can ask the question which of my books describes it. But we cannot choose that book, only recognize that it has a certain relationship to the world in which I am surveying the books. It would invole self-referentiality, but I think you have already accepted that.

I'm trying to explain this by positing two different contexts (points of view) - the context of the world according to modal logic and the context of ordinary life. It's not a problem unique to modal logic or logic in general. It's a problem for physics as well. Perhaps even for philosophy.

Oh, yes - I emphatically agree - natural language comes first; indeed I'd suggest that formal logic is just a game within our natural language, and not something seperate from it. — Banno

It does seem that we are on the same page after all.

So, what conclusions do we draw here? — Banno

I don't know about conclusions. However, I do think that a practice that pays attention to cases and sometimes is happy to jump one way and sometimes the other is all that is appropriate. (I like Wittgenstein's ideas of a) a map - knowing one's way about and b) philosophy as giving peace from certain kinds of torment - notably the torment of being bewildered in a world that ought to make sense.
I would put in a word for fun and curiosity as well.

I do not see the problem; could you say it in another way? — NotAristotle

All the talk of "Aristotle" referring to Aristotle is all very well - if the metaphysical link is all that matters. We can agree that the link exists, in some sense. But "Aristotle" has another life, in language and the use that people make of it. A referential link that obtains whether or not it is known to language users will not explain how language works, or, more accurately, how we make language work. Note that without language and its speakers, metaphysical truths cannot be formulated, never mind communicated.
Does that help?

What does “water” mean? "Water" means different things to different people. To a scientist, "water" is necessarily H2O. To me, "water" is necessarily wet, in that if not wet it cannot be water. To a linguist, “water” is necessarily a noun. There is no one meaning of “water”, though each meaning is necessary within its own context. — RussellA

And yet all these people can communicate. How is that possible? There must be common elements to all these different meanings that enable communication across contexts. Those common elements are what we might call ordinary life, which is the common context that links all three people.

The challenge is to use formal grammar to exhibit the incoherences and inconsistencies in our philosophical meanderings. It's not picking a logic that gives the answer we want, but looking at what we have to say using formal tools that set out clearly the problems. — Banno

A standard of clarity. Tempting, very tempting.
But you quoted Austin -

"Real" is best treated as Austin suggested, as a relative term - it's not real, it's a counterfeiter; it's not real, it's artificial... and so on. — Banno

I think he would have take issue with you. So perhaps I can suggest that things are not anything like as clear as you seem to propose here.
Ryle, in "Dilemmas" draws an interesting distinction between technical and untechnical concepts, which clarifies, to some extent, his talk of parade ground language and informal logic. The point about ordinary language, for him, is that it is inescapable and even technical concepts rely on it. To put it another way, formal logic starts from ordinary language, which remains basic to our understanding. Formal languages are in that sense parasitic. (Scientists, mathematicians, logicians all live and work in the ordinary world,)
Surely I don't need to try to summarize Wittgenstein's critique.
Which is not to say that formal logic never does the job you identify for it. Whether Russell's theory of descriptions is correct or not, it is, to my mind, a good example of what can be done.
But formal logic has problems of its own. The logical explosion (ex falso quodlibet - from a false proposition anything follows) is a good example - to my mind, at least.
Even modal logic has issues. Trans-world identity seems to be one of them.
Perhaps that is enough for present purposes.

Water is necessarily H20 even before anyone knew that this was the case. — RussellA

Well, you/Kripke have your reasons for saying that, I suppose. But it is clear that whatever "water" means is not based on that information.

Aristotle is necessarily Aristotle even if no one knows it. — RussellA

Again, perhaps so. But it follows that, whoever is called Aristotle is not necessarily the philosopher that we know and love.

Well if they aren't using the term the same way I would think that they would not get the meaning. If the meanings of the speaker diverge, they cannot have a discussion; but this appears to be something like a rule of conversation (see rules of conversational implicature by Grice). — NotAristotle

But Kripke thinks that those are the possible ways of fixing the reference of any term. So the whole practice of referring becomes pointless.

It is a separate question how such speakers come to agree on the meaning of a term. — NotAristotle

Yes, but isn't this the question that matters. A reference that cannot be used is utterly pointless.

For the Indirect Realist, we only know the actual world as representations in the mind, .... — RussellA

Clearly, I'm not a indirect realist, because I don't accept that we only know the actual world as representations in the mind, because, as Berkeley pointed out, unless you can compare a representation with its original, you can't establish what, if anything, it is a representation of.

...whereas for the Direct Realist, we directly perceive an actual world existing independently of our representations of it. — RussellA

Clearly, I'm not a Direct Realist because I don't accept that we directly perceive an actual world existing independently of our representations of it.

I don't think that "directly" and "indirectly" are applicable in this context and I have my doubts about "real", because "unreal" in this context does not have a clear meaning.

That Aristotle is the same individual is not because of any knowledge about his essence or identity, but because of a casual chain linking Aristotle back through time to being the son of his parents at the moment of his baptism. — RussellA

The implication is that the existence of the causal chain is necessary and sufficient, presumably whether or not we know it. That's extremely hard to understand, because it suggests that we do not necessarily know who Aristotle is, if anyone.

IE, it is wrong to say that there are actual possible worlds. — RussellA

I would agree with you if you mean that the idea of a possible possible world is incoherent. But all possible worlds are possible actual worlds. When we designate one of them, we are making that possibility actual. We do not make the possible world vanish and an exactly similar, but numerically different actual world appear.
The candidates in an election are all possible office-holders. When one of them wins, that very same possible office-holder becomes an actual office-holder. It is very confusing to think of that office-holder as an actual possible office-holder, but very easy to think of that actual office-holder as an erstwhile possible office-holder.

The take-away: the structure of possible world semantics that Kripke set up has been used to formalise a wide variety of situations by amongst other things constructing suitable accessibility relations. Since these are dependent on the core possible world semantics, it might be good practice to make sure we understand what that is before we go off talking about these applications of that logic. — Banno

I think I understand all that. We seem (not only in this context, but in most modern discussions of logic) to have got to a situation where what logic one uses is just a function of what project one is pursuing. Logic as pragmatism. Is that grossly unfair?

In other words, if my composition of H2O and NaCl is what determines what I am referring to, then yeah, that would also determine what is meant by water. On the other hand, if what I mean by water is in some sense prior to or co-relational to the thing in the world that is being picked out, then I am not so sure that we have to use the actual-world instantiation of something when we refer. — NotAristotle

It looks as if you are saying that what determines reference is simply a question of how each speaker is using the word. I can see a sense in which that is true. But then I want to know how it is that other people can "get" what I am referring to, given that they may or may not be using the word in the same way as the speaker.

There is no need to appeal to essences in all possible worlds to understand what the name is referring to in this example (sc. "warder" is s composed of 98% H2O and 2% NaCl). — Richard B

It does seem obvious that the way a community refers to something cannot be determined by all possible future discoveries about that substance. We have to adapt how we refer to things as we go along - future cases are determined as they crop up. It seems to me that rigid designation sweeps away all the problems in pursuit of the timeless present.

This is the problem Kripke has with using the natural language term "water" and trying to call it identical with the scientific term "H2O". His only choice is to massage that vague term "water" into a precise term like "H2O" to fit in with his domain of logic. — 'Cartesian Linguistics' - James McGilvray

That's exactly right. But I would say that "massaging" our meanings is how we manage things. Our critique ought to not to target the massaging, but the sad consequence that we end up with a misleading view of our world.

I think the real answer here is it does not matter what you say, only what we humans agree upon. — Richard B

I would agree. But we need to give more of an answer to those who think it does matter. There is what may be a side-issue, but we need to be aware that just as there are many things that humans agree on, there are also many things that they disagree on. Paradoxically, human agreements may also be the frame of human disagreements.

No, that's not what contingent means. Suppose necessitarianism is true. Necessitarianism is the theory that every that event that occurs (past and future) occurred necessarily. — Relativist

I agree with you. Necessitarianism does seem to sweep the concept of contingency away. So we need to show why we need it. I don't have an answer.

Actual worlds may exist or possibly exist. — RussellA

We have to be very careful about our terms here. As a result of reading this thread, I have become quite confused about what "actual" actually means (!) and how it relates to "exists" (and "real"). I don't see how actual world could only possible exist. It seems to mean something close to "exists" and like it, in that neither are, in Kant's sense, predicates. (Nor, come to think of it, is "real")

But let's forget about that." -Naming and Necessity p43
If he can't account for identity over time, then he can't account for true trans-world identity either — Relativist

I think you misunderstand Kripke's project. It is, it seems to me, to find a way of forgetting about everything that makes a problem for the project of logic. In which, perhaps, he succeeds. Then we will ask more pragmatic questions about the project.

...every concept we have misleads intellectually by producing the illusion that something not understand is understood. — RussellA

I think that's far too strictly binary. Understanding is not a whole, but is (almost always) partial. No single concept can cater for all contexts, but they can be useful and helpful in some contexts. That is enough.

Well, since we were talking about suicide, I thought it understood that we were talking about the life in question. Sorry for the imprecision. — Questioner

Not an unreasonable assumption. But I wanted to put owning a life into a context that made it clearer, IMO, how absurd the idea of owning one's own life is.

Just a note - if it's assisted death we are talking about, it is not referred to as euthanasia, which removes the agency of the person making the decision. — Questioner

You are right. I'm a bit old-fashioned and forgot about this.

Who owns a life?
Do obligations to others supersede that ownership?
Is interference in one's desire to kill themselves morally sound? — Questioner

1. The question is badly formulated. If someone owns a life, that is slavery. The idea that I might or might not own my own life is meaningless. But if you are asking, who has the right to make decisions such as ending a life, it seems crystal clear to me that only I can decide to end my own life. What about capital punishment? I oppose that. What about the life of someone who is not competent? That's much more difficult. But this thread is about suicide, so those situations are off topic.
2. DIgnitas are very clear that people contemplating their euthanasia should talk to their nearest and dearest and do their very best to persuade them to accept their decision. But there's a corresponding obligation, I think, on relatives not to unreasonably oppose it.
3. It depends on the details of the case. But sometimes it is not - and sometimes it is.

I don’t know if that’s true. I am currently well and healthy, but I want to retain the option of ending my own life if circumstances deteriorate. If I were to develop a terminal illness that involved significant suffering, I would want that option available. — Tom Storm

Me too.
I have heard that in Canada, it is not unusual for people to go through the procedure for euthansia but never use it.

DIGNITAS’ experience shows that only a very few people who enrol as members take advantage of the service for assistance with suicide. They usually feel sufficiently protected by the Patient’s Instructions. If these are observed – because they specify that no life prolonging measures are to be initiated – any life-threatening situation will lead to a natural death. Membership of DIGNITAS endows members with confidence: in the event of a hopeless situation, a member can say “I have had enough now, I want to die.” This feeling of security is of exceptional importance to mature human beings. — Dignitas Information Brochure

Don't forget about the instruction not to prolong life unnecessarily. It has legal force in many countries, though it goes by different names.

I read Naming and Necessity some years ago. Later, I read Mackie's How Things Might Have Been*. The latter was written after Kripke's work; she references Kripke, Lewis, Plantinga, and others - and demonstrates the problems I have been relating to you. Responding, "but Kripke said...." is not a refutation. — Relativist

H'm. I thought @Banno was only aiming to explain Kripke's system as being the one that is most widely accepted in the relevant discipline.

trans-world identity is controversial. Kripke does not solve the contoversy- he just alligns to one side of it. — Relativist

That's one of the reasons I can't accept the possible worlds device as anything but a way of making a formal logical system for possibility and necessity. Kripke sweeps away all the philosophical problems by inventing rigid designation.

This is the issue Banno and I debated endlessly in the other thread. The position that Banno insisted on, which I insisted is clearly false, is that the actual must be possible. This means that the actual world (and this is the factual "actual world") must be a possible world. — Metaphysician Undercover

It seem that you and @Banno had incommensurable views. He was explaining Kripke's views, and I've benefited by getting a better understanding of what those views are. But to understand K, I think you have to understand what he is proposing. I proposed earlier that we think of the description of each possible world should be thought of as a book on a shelf; then the description of the actual world can be placed on that same shelf and thought of as a possible world along with all the others. We can take any book off the shelf and think of it as the actual world. So any world can be thought of as a possible world and that same world can also be thought of as the actual world.
Think of it this way. You are being asked to set aside the world as you know it and think about a different world. One's thinking in this mode involves suspending (bracketing) one's normal beliefs and disbeliefs. So, the world in which one is performing this thought experiment is set aside. While you are experimenting, we think of that world and the goings-on in it, as real. When we switch back to normal life, the actual world, in which all those books exist and we choose to take one off the shelf becomes, again, part of our thinking.
You may be thinking that this is all just pretending, but it is something was can do. It is how fiction ("Pride and Prejudice" or "Star Wars") works. You probably know Coleridge's phrase about the suspension of disbelief and his recognition that in some ways it is special, even weird. But it is clear that we can do it.
I don't think there is much difference, though, between thinking about a different world, in which, for example pigs and horses can fly and imagining that pigs and horses can fly. Kripke seems to think not.
That's why he proposes that we treat all possibilities in this same way. So perhaps we should only think of this as a fancy way of thinking about what would have been different if Nixon had lost the election. If it works for his project, it is justified.

Since possibilities can be boundless, any set of possible worlds which we produce can never be "in fact the set of all possible worlds". — Metaphysician Undercover

If possibilities can be boundless, it follows that they might not be. In that case, we can produce a set of all possible worlds. But we can define the set of all natural numbers, prove that it is infinite, and still calculate.

The possible worlds we present, are really ideas which we produce. But it is implied that there is an independent set of all possible worlds. — Metaphysician Undercover

The distinction between an idea and what it is an idea of what is sometimes called it's object, even though it may not be an object at all in the other sense of the word, is implicit in the idea of an idea. You seem to confuse the two when you say that the possible worlds are really ideas.
To understand this, may I go back to Frodo (just for the sake of an example).

Frodo" refers to Frodo, a fictional character in LOTR. It does not refer to the idea of Frodo.— Banno
A fictional character is an idea, not a thing. — Metaphysician Undercover

This is more complicated than it may appear. An idea is defined by reference to what it is an idea of. The idea has no existence without reference to its object. It is, in that way, parasitic on its object. But in some cases, the object of an idea may not exist, as in the case of Frodo. Here, we are presented with all the descriptions that we normally use to describe something in the world, but there is no such thing in the world. So, does Frodo exist or not? He is a fictional character, and so the answer must be, No. But there is an idea of him, which is created by the stories about him. So the answer must be Yes. Classic philosophical stuff, produced in the familiar way by extending the rules of a language game into a context where standard interpretations do not work, and we must decide how to apply the rules.
What we cannot do is say that Frodo is an idea, because ideas and people are objects of different categories. So we say, for example, that Frodo subsists or some such phrase. Perhaps better is to say that he is a fictional character, which means that he exists in the mode that fictional characters exist in, which, I accept, is to say nothing. In the end, we can work with this paradox without much trouble, so we do not need to resolve the problem, but only recognize it.
:LOTR is a possible world, in some sense of possible. So this problem, and its non-solution, apply to possible worlds, as well as fictional ones.
Do we want to say that possibilities exist or are real independently of our ideas of them? It could go either way. But what we cannot say is that ideas of possibilities can exist independently of the possibilities that constitute their objects. The dependence only goes one way.

The modern logician says, “For all x…,” but when asked what he actually means by ‘x’ he has no idea. He doesn’t know whether imaginary entities count, or whether theoretical entities count, or whether propositions themselves count, etc. In essence he does not know to which of the categories of being his quantifier is supposed to apply, and his presuppositions ensure that he will be unable to answer such a central question. — Leontiskos

I thought the point of modern-style logic was precisely to avoid metaphysical issues. Anything that is distinguishable as a distinct entity (within its category) can be substituted into the formulae, provided a suitable domain is defined for the variables. But the formal system is independent of that definition. Hence Quine's "To be is to be the value of a variable". Which doesn't solve any metaphysical problems, but then, I doubt if it was supposed to. But perhaps I've misunderstood.