Because the difference is not modal. It's metaphysical. — Banno

I wouldn't argue about that. But I don't thoroughly understand either or metaphysical. So I prefer to say that it's a question of how you look at it - or represent it.

But I don't thoroughly understand either or metaphysical. — Ludwig V

Good, since it is a topic of ongoing discussion. Just not much in the way @Metaphysician Undercover suggests.

You have not addressed this question: — Metaphysician Undercover

The philosophy behind actual versus possible is lengthy and complex. If you want to walk through two SEP articles on it we can examine the views of all the interested parties. There's even a tie-in to negative dialectics!!!

I've explained what possible worlds are and how the actual wold is a possible world. If there is a problem set it out. The view I've set out it quite standard. If you see it as problematic, set out how. — Banno

I did set it out. This will be the third time I post the very same paragraph. Please, could you read it and reply accordingly. This is it:

So to reply to your SEP article, human beings think that "things might have been different in countless ways". These different ways that human beings think that things might have been different, are thought up by human beings, and so they are not independent from us. Therefore, "possible worlds" are worlds which are not independent from us, they are dependent on us. If, "the actual world" is said to be one of the possible worlds, then the actual world is not independent from us. Possible worlds are not independent. — Metaphysician Undercover

The possibility that it will rain tomorrow does not depend on whether we recognize it. — Ludwig V

Yes it does, very explicitly, it is something very specific, that human beings draw up in words, "the possibility that it will rain tomorrow".

The trouble is that we cannot know what they are. — Ludwig V

Of course we cannot know what they are because they cannot exist. The existence of statements is dependent on human beings. How could there be statements which we cannot know what they are, when a human being must have made the statement?

If the actual world was not a possible world, then it could not exist. — Ludwig V

That's nonsense. The possibility for something, precedes in time the actual existence of that thing. Once it is actualized, it is not longer a possibility, but an actuality. Suppose president Trump is actually assassinated. At this time, Trump has been assassinated, is a true statement of the actual world. At this point it is not possible for him to be assassinated, because he already has been.. So it's nonsense to think that if, in the actual world, Trump has been assassinated, it must be possible that Trump could be assassinated, because it is actually impossible, as he has already been assassinated. The same must be true of every actuality, and "the actual world" in general. Once it is actual, it is false to claim that it is possible.

There is no modal difference between the actual world and the other possible worlds... That'll confuse Meta no end. — Banno

It doesn't confuse me, I fully understand this, and it is the base of my argument. If you understand this, then it is undeniable that realism is incompatible with modal logic. Obviously, realism requires a difference between possible worlds and the actual world.

ecause the difference is not modal. It's metaphysical.

And Meta, as I've pointed out, has failed to see this distinction. — Banno

As I've told you, to have inconsistency between your metaphysics and epistemology is to have contradictory philosophy. To say that in my epistemology "the actual world is the same as any other possible world", but in my metaphysics "the actual world is completely independent and different from possible worlds", is nothing but contradiction within your concept of "actual world".

The philosophy behind actual versus possible is lengthy and complex. If you want to walk through two SEP articles on it we can examine the views of all the interested parties. There's even a tie-in to negative dialectics!!! — frank

Whatever you wish, I'm willing to follow.

The philosophy behind actual versus possible is lengthy and complex. If you want to walk through two SEP articles on it we can examine the views of all the interested parties. There's even a tie-in to negative dialectics!!!
— frank

Whatever you wish, I'm willing to follow. — Metaphysician Undercover

Are you serious?

I've answered already. Several times. Here's the best I am willing to do.

The song remains the same.

I've answered already. Several times. Here's the best I am willing to do. — Banno

That's not very good. Where's the answer?

Here's an example of the contradiction you fed to me in that link:

They [possible worlds] are semantic or metaphysical constructs used to interpret modal statements.

They exist (or are defined) independently of human imagination. — CHAT GPT

"Constructs" which are independent from human imagination. Who constructs these metaphysical constructs if not human beings?

From the fact that humans think about alternative possibility-structures, it does not follow that those possibility-structures depend on human thought. — CHATGPT

Duh, the possibility structures are the thought ("constructs"), produced by the minds that think them. Are you arguing Platonism now? 'From the fact that human beings think ideas, it doesn't follow that ideas are dependent on human thought''. What about the "construct" part boss?

Come on Banno, quit the bullshit and say something real.

Why should a semantic model commit us to the existence of the things quantified over? Your whole edifice still depends on an equivocation between what is and what is said. It's as if you were to chastise Tolkien because Hobbits are not real. nThe confusion is yours.

If the actual world was not a possible world, then it could not exist. — Ludwig V

Something is very puzzling on what is being said here. It suggests colorful scene, as if I should go to a private room close by eyes and think about three possible worlds, then, upon opening them I realize that one of the three was the actual world around me and thus, I conclude, all in one fell swoop, one of the possible worlds I consider was the actual world and it exist too. Now I can say to myself, "If the actual world was not a possible world, then it could not exist."

It reminds me of what Wittgenstein said in the Tractatus in section 5.5303 "Roughly speaking, to say of two things that they are identical is nonsense, and to say of one thing that it is identical with itself is to say nothing at all.

It seems to me that the what is be said, that "If the actual world was not a possible world, then it could not exist." seems to fall in the latter camp, that it is to say nothing at all.

Why should a semantic model commit us to the existence of the things quantified over? — Banno

The semantic model does not commit us to the existence of its content. But if the actual world is affirmed to be a part of that semantic model, as you and others here continue to insist, then this is contrary to realism which assumes that the actual world is independent from any semantic model. Why is that difficult to understand? You can't have it both ways, assert that the actual world is a part of a semantic model, with no claims to existence, and also assert that there is a real independent, existing actual world.

Your whole edifice still depends on an equivocation between what is and what is said. — Banno

The point is, that when you claim that the actual world is one of the possible worlds, you deny that there is a distinction between what is said and what is. If you assert that there is another "actual world" which is independent from what is said (realism), as well as the "actual world" which is part of the semantic model, then you equivocate. The equivocation in my "edifice" is just a reflection of the equivocation in what you are telling me, which my edifice is built upon. You are telling me that there is a metaphysical "actual world" and an epistemic "actual world", and the use of these contradict each other.

The solution to this problem is to maintain the distinction between the actual world and the possible worlds, i.e. the actual world is not a possible world. But as soon as we accept the proposition "if it is actual, it is possible" we negate that distinction and we are left with either a denial of realism, or a contradictory equivocation.

Are you serious? — frank

Sure, you start the thread, I'll follow.

The possibility for something, precedes in time the actual existence of that thing. Once it is actualized, it is not longer a possibility, but an actuality. — Metaphysician Undercover

Someone in the next room flips a coin. We cannot see the result. Now we ask the question - is it possible that the coin is showing heads? The answer is of course yes. Then we walk into the next room and indeed the coin is showing heads.

So while it is not necessarily so (the coin could be tails), something can be both possible and also be real/actual at the same time.

So while it is not necessarily so (the coin could be tails), something can be both possible and also be real at the same time. — EricH

I am a little unclear on what you mean here. When you say “something can be possible and real at the same time” what are you referring to when you say “something” The real coin? So, a real coin that landed on heads is the same as a possible coin that may land on heads.

This was in direct response to @Metaphysician Undercovers statement:

The possibility for something, precedes in time the actual existence of that thing. Once it is actualized, it is not longer a possibility, but an actuality. — Metaphysician Undercover

MU is using a very loose definition of the word "something" here - I take it to mean a state of affairs (e.g., a coin displaying heads at a particular place and point in time). MU is stating that it is impossible for "something" to be a possibility as well as an actuality at the same time. I am simply pointing out what appears (at least to me eyes) to be a very obvious exception.

If you need further clarity as to what "something" refers to, you'll have to go to the source: https://thephilosophyforum.com/discussion/comment/1028434

Now I can say to myself, "If the actual world was not a possible world, then it could not exist." — Richard B

One of the ways of seeing this is more or less what you describe. One can think of possibility as a kind of ante-chamber to existence. So all sorts of possibilities (possible worlds) hang about in there, waiting to be promoted. It does capture, in a metaphorical way, that our actual world has had a previous quasi-
life.

It seems to me that the what is be said, that "If the actual world was not a possible world, then it could not exist." seems to fall in the latter camp, that it is to say nothing at all. — Richard B

You could say that. It's not exactly analytic, but it is trying to capture (express/show) a conceptual relationship.

The possibility for something, precedes in time the actual existence of that thing. Once it is actualized, it is not longer a possibility, but an actuality. — Metaphysician Undercover

I'll give you this - I cannot win the 2025 Kentucky Derby twice. But that's not because I won it, but because it has happened that the result - win or lose - is settled. But if whatever the result of the 2025 race, it remains possible for me to win the 2026 race. So the possibility of my winning the Kentucky Derby does not cease when I win it.

So while it is not necessarily so (the coin could be tails) — EricH

That's a nice example. But it needs a bit of caution. While I do not know what the result is, I can say "The coin could be tails", but if I say it while I'm looking at the result, I'm falling into the sceptical morass. After you know the result, you need to say "the coin could have been tails".

The existence of statements is dependent on human beings. — Metaphysician Undercover

That's true. But the fact that the existence of the statement that Mount Everest is 29,000 ft high depends on human beings, does not show that the existence of Mount Everest depends on human beings at all. De re and de dicto.

The semantic model does not commit us to the existence of its content. But if the actual world is affirmed to be a part of that semantic model, as you and others here continue to insist, then this is contrary to realism which assumes that the actual world is independent from any semantic model. — Metaphysician Undercover

As if we could not talk about the actual world.

You can't have it both ways, assert that the actual world is a part of a semantic model, with no claims to existence, and also assert that there is a real independent, existing actual world. — Metaphysician Undercover

Because, as explained many times, it's not the semantic model that shows which possible world is actual.

But you cannot see this. That's about you, I suppose.

That's true. But the fact that the existence of the statement that Mount Everest is 29,000 ft high depends on human beings, does not show that the existence of Mount Everest depends on human beings at all. De re and de dicto. — Ludwig V

Thank you.

Sure, you start the thread, I'll follow. — Metaphysician Undercover

Ok. I'll post chunks of the SEP articles and comment. The goal will be to sort out the different perspectives on possible worlds and the ontological status of possibilia.

Someone in the next room flips a coin. We cannot see the result. Now we ask the question - is it possible that the coin is showing heads? The answer is of course yes. Then we walk into the next room and indeed the coin is showing heads.

So while it is not necessarily so (the coin could be tails), something can be both possible and also be real/actual at the same time. — EricH

I went through this all, way back. When we know that the coin is showing heads, it is incorrect to saying it is possible it is heads. When we do not know that the coin is showing heads it s correct to saying that that it is possible the coin is showing heads. Your example refers to two different times, before walking into the room, and after, so your conclusion of "at the same time" is incorrect. Before walking into the room we say it is possible, and after, we say it is actually showing heads, and we can no longer say it is possible. There is no "at the same time" indicated.

I'll give you this - I cannot win the 2025 Kentucky Derby twice. But that's not because I won it, but because it has happened that the result - win or lose - is settled. But if whatever the result of the 2025 race, it remains possible for me to win the 2026 race. So the possibility of my winning the Kentucky Derby does not cease when I win it. — Ludwig V

How's that relevant? You change from a specific possibility to a more general, so it is a different referent.

That's true. But the fact that the existence of the statement that Mount Everest is 29,000 ft high depends on human beings, does not show that the existence of Mount Everest depends on human beings at all. — Ludwig V

Again, I don't see the relevance. What I was responding to was unknown true statements, not unknown things.

If we look at EricH's example of the coin, there is implied an unknown real thing, the coin before looking at it. But that is not a statement, it is simply something unknown.

As if we could not talk about the actual world. — Banno

Why does what I say to you indicate that we cannot talk about the actual world? How can you make such a conclusion from what I wrote? What I said, is that if we are realist, we cannot put "the actual" into a semantic model in which it is a possible world. That would contradict our realist principles. In no way does it imply that we cannot talk about the actual world. It only implies that we cannot talk about the actual world in that specific context, because that would contradict our realist principles.

Because, as explained many times, it's not the semantic model that shows which possible world is actual. — Banno

That doesn't matter. By the principle upon which the semantic model is produced, we cannot conclude that any of the possible worlds is the actual world without contradicting realist principles. If you take a set of possible worlds, and apply some realist principles to deduce "the actual world", then you must relinquish the claim that the others are possible. You are then not within the constraints of the semantic model, so the other worlds are no longer "possible". "Possible" is a word applied in a very specific way, within that model, and you have moved outside that model, so the application is not valid.

Look what you said already yesterday:

"There is no modal difference between the actual world and the other possible worlds... ".

That is the very issue with modal models, by what principles do we produce an actual world. When you apply some principles to designate "the actual world", you violate the modal model by assigning special status to one of the worlds, placing yourself outside the model, and no longer correct in referring those other worlds as "possible". We only have those "possible worlds" within that semantic model which denies any such special status to any world. Assigning special status violates the model.

If you take a set of possible worlds, and apply some realist principles to deduce "the actual world"... — Metaphysician Undercover

Again, again, again, That's not what is being proposed. Any of the possible worlds could be the actual world - hence, "there is no modal difference between the actual world and the other possible worlds". Modal theory does not tell us which possible world is actual.

Your presumption that it does is exactly your confusing the modal and the metaphysical, your denial of p→◇p.

This is a pretty tedious conversation. You make the very same error, repeatedly. The actual world is one of the possible worlds. If you deny this, you must also deny reflexivity, which is to say you deny that we can talk about the actual world. You restrict yourself to quite simplistic and unusable modal systems.

All of which was set out formally, last week, and remains unaddressed.

But it's helping my post count. So carry on.

How's that relevant? You change from a specific possibility to a more general, so it is a different referent. — Metaphysician Undercover

So for some p, the possibility of p ends when p occurs and for other p it doesn't. Furthermore, the ending of the possibility of my winning the Kentucky Derby 2025 does not depend on whether I win or lose or even take part. It depends only the the race happening. The disappearance of this specific p depends only on the date, not on whether I win or not.

What I was responding to was unknown true statements, not unknown things. — Metaphysician Undercover

Yes. You are right about that. I took the original claim in a generous senses, that would see it as equivalent "unknown truths"

If we look at EricH's example of the coin, there is implied an unknown real thing, the coin before looking at it. But that is not a statement, it is simply something unknown. — Metaphysician Undercover

So do you accept that there are some unknown things?

So for some p, the possibility of p ends when p occurs and for other p it doesn't. Furthermore, the ending of the possibility of my winning the Kentucky Derby 2025 does not depend on whether I win or lose or even take part. It depends only the the race happening. The disappearance of this specific p depends only on the date, not on whether I win or not. — Ludwig V

Yep. This is formalised by accessibility relations. metaphysically, before the race is run, both the worlds in which you win and those in which you do not are accessible; any might become the actual world. After you win, only the worlds in which you win are accessible. Semantically, both before and after the race is won, we can access both the worlds in which you won and those in which you did not.

Conflating these is the exact error Meta repeatedly makes.

Any of the possible worlds could be the actual world - hence, "there is no modal difference between the actual world and the other possible worlds". Modal theory does not tell us which possible world is actual. — Banno

That's an incorrect interpretation, for obvious reasons. None of the possible worlds could be the actual world, as that would constitute an invalid difference, within the collection of possible worlds, one would be the actual world. Therefore it is clearly not the case that one of the possible worlds is the actual world because that would invalidate the model. Therefore we must interpret that none of the possible worlds is the actual world.

So for some p, the possibility of p ends when p occurs and for other p it doesn't. — Ludwig V

Yes, this acknowledges the difference between a particular and a universal. So you use "p" in an equivocal way. "When p occurs" refers to a particular, while "other P" refers to a type. It is clear that "when p occurs" must refer to a particular, because if it was a type, an instance of p occurring would not preclude the occurrence of another instance of p. But, the occurrence of a particular precludes the possibility of that same particular occurring again. So, we must clear up the equivocation in that statement, where "p" refers to a particular, and also to a type.

So do you accept that there are some unknown things? — Ludwig V

I believe there is a lot which is unknown. Strictly speaking it would not be correct to call the unknown "things", because that implies some sort of knowledge of the unknown, knowledge that the unknown consists of things. In other words, saying that there is "unknown things" wrongly projects knowledge onto the unknown. This is similar to, but more subtle, than saying that there is unknown statements. "Unknown statements" is obviously a problem, even to those without metaphysical education. But "unknown things" requires metaphysical understanding to recognize as fundamentally incorrect.

None of the possible worlds could be the actual world, as that would constitute an invalid difference, within the collection of possible worlds, one would be the actual world. — Metaphysician Undercover

Risible.

One of the possible worlds is the actual world.

Either that, or the actual world is not possible.

Your example refers to two different times, before walking into the room, and after, so your conclusion of "at the same time" is incorrect. Before walking into the room we say it is possible, and after, we say it is actually showing heads, and we can no longer say it is possible. There is no "at the same time" indicated. — Metaphysician Undercover

The person who flipped the coin knew it. At the same time.

Risible.

One of the possible worlds is the actual world.

Either that, or the actual world is not possible. — Banno

Exactly.

Within the modal model, we now have two possibilities, "one of the possible worlds is the actual world", or "the actual world is not possible". Since it violates the rules of the model for one of the possible worlds to be the actual world, then within the modal model, the actual world is not possible. Therefore model logic is not consistent with realism.

I'm glad you are at least starting to consider this as a possibility.

That's why ontologies like model-dependent realism are not true realism. Here's an analogy which might help you to understand. Under relativity theory, any rest frame is a valid rest frame, and each frame is made to be consistent with each other, as a valid "possibility". Each is a "possible" frame of reference, but none provides a true rest frame, which would be the "actual rest frame". In order that all the frames of reference may equally be valid rest frames, it is imperative that none is the "actual rest frame". Likewise, in modal logic it is imperative that none of the possible worlds is the "actual world", or the possibility of the others is invalidated.

The person who flipped the coin knew it. — EricH

You are changing to a different definition of "know", a subjective one, claiming that one person knows what others do not. We have been discussing this issue under the premise that knowing is a property of "we", not the property of one individual subject. I cautioned against equivocating between these two senses of "know" a few days back, because the conditions are completely different.

So in your example, there is a number of people, and discrepancy between what one person thinks that they know, and what others think that they know. Therefore it does not qualify as "we know", and is not a valid example. Anytime that it is proposed that there is inconsistency between what one knows and another knows, or between what some know and others do not, it is not a case of "we know", and not a valid example for the purpose of this discussion.

Since it violates the rules of the model for one of the possible worlds to be the actual world — Metaphysician Undercover

:roll:

It doesn't.

his is formalised by accessibility relations. metaphysically, before the race is run, both the worlds in which you win and those in which you do not are accessible; any might become the actual world. After you win, only the worlds in which you win are accessible. Semantically, both before and after the race is won, we can access both the worlds in which you won and those in which you did not. — Banno

This is hard to decipher into my idiolect. Before the race I can access two possible worlds, the one in which I win and the one in which I don't. After the race, only the world in which I win is accessible. Going by what you said to Meta "One of the possible worlds is the actual world", that world - in which I win - has become the actual world.
I don't understand the bit about semantics, and how they enable me to do something I can't do metaphysically. I think you may be referring to the point that after the race, "I might have lost" is true. ?

So, we must clear up the equivocation in that statement, where "p" refers to a particular, and also to a type. — Metaphysician Undercover

Yes. No more "a possibility" or "an actuality". We'll need to specify whether we are speaking about a particular or a general/universal possibility/actuality.

Strictly speaking it would not be correct to call the unknown "things", because that implies some sort of knowledge of the unknown, knowledge that the unknown consists of things. — Metaphysician Undercover

I take your point. Perhaps we should restrict ourselves to talking of "the unknown". It might clearer to change tack and only talk about the possibilities of discovering new knowledge.

If we look at EricH's example of the coin, there is implied an unknown real thing, the coin before looking at it. But that is not a statement, it is simply something unknown. — Metaphysician Undercover

That's an example of using thing in a generously vague way. It is useful because it avoids annoying debates about what is a thing and what is not, etc;

So while it is not necessarily so (the coin could be tails), something can be both possible and also be real/actual at the same time. — EricH

I'm afraid this doesn't address the problem, but it is a nice try. The possibility and the actuality exist in different contexts. From outside the room, it is possible and from inside the room, not. What's at stake is the P implies possibly P. That means within a single context.

It doesn't. — Banno

You yourself said:

"There is no modal difference between the actual world and the other possible worlds... "

Therefore if we assign to one of the possible worlds the status of "actual world" by realist principles, (which would constitute a modal difference), we would be attributing a difference to this world which violates the modal system which dictates "no modal difference".

No wonder I'm so confused, you keep making contradictory assertions without backing any of them up. Without the proper support for these assertions, I can 't tell which of the contrary claims you actually believe. Therefore I can only conclude that you just don't understand what you're talking about.

I take your point. Perhaps we should restrict ourselves to talking of "the unknown". It might clearer to change tack and only talk about the possibilities of discovering new knowledge. — Ludwig V

This is good. Now we have the basic separation between Platonic realism and non-Platonic types of realism to navigate. Notice you mention "the possibilities of discovering new knowledge". That knowledge is something independent from human beings, which is "discovered" by us implies Platonism. This form of realism is conducive to the idea that there is unknown true propositions, which exist independently from us, which we "discover".

The alternative, non-Platonic realism would say that we create, produce or "construct" knowledge while something other than knowledge is what is independent from us. There are also forms of realism which blur the boundary between these two by invoking concepts like "information".

That's an example of using thing in a generously vague way. It is useful because it avoids annoying debates about what is a thing and what is not, etc; — Ludwig V

It might avoid such debates, but if we want to understand the metaphysics, and the possibility of the reality of an independent world, we need to engage these difficult subjects. Mundane life, and common language use in general, for communication, has no need for metaphysics. So habits of language usage are developed in ways of ambiguity, the ambiguity providing for a difference in underlying world-views. The ambiguity is effective in allowing me to interpret by my world-view, and you to interpret by your world-view, such that we can effectively communicate and move along in our day to day projects without the need for consistency between our ontological foundations.

So we can avoid "annoying debates about what is a thing and what is not", and move along with our mundane communications without the need to address metaphysical differences. If however, metaphysics is the subject of discussion, then avoiding these annoying discussions is a mistake conducive to misunderstanding.