You stipulate that you are talking about the actual world, and this means that the world you are talking about is a possible world, it is stipulated. By your own words, the actual world is "not stipulated". — Metaphysician Undercover

We are in the actual world. Metaphysics.

We might stipulate that we want to talk about the actual world, and not some other possibel world. Semantics.

You are mixing the two.


If you stipulate that the world which Branson's wife did not die, is the actual world, you would be mistaken.

We are in the actual world. Metaphysics. — Banno

OK, let's get this straight. I hope you are not trying to confuse me.

We are in the actual world.
Possible worlds are stipulated though.
The world we are in is not a stipulated world
Therefore the actual world is not a possible world.

Agree?

The world we are in is not a stipulated world — Metaphysician Undercover

This is a metaphysical point. The other assumptions are semantic.

Speaking semantically, the actual world can be stipulated. Which is just to say we can talk about the actual world as one of the possible words.

We are in the actual world. — Banno

What proof do you have of such that a person in a stipulated or even flat-out simulated world wouldn't be able to "show" or otherwise "point to" as well, though? This is the root of the argument that words and misplacement of words ultimately fail to address. :chin:

Not sure I understand.

By definition, the actual world is the one we are in. Is that what you are asking?

Or are you asking for proof that you are in the actual world? What could that look like?

This is a metaphysical point. — Banno

A very important metaphysical point, I might add. Failure to recognize this might lead one to think that the actual world is one of the possible worlds. And one might think that what is actually known is also possibly known. But a good metaphysician will recognize the category division, and the danger of contradiction if we allow that the actual is also possible.

Speaking semantically, the actual world can be stipulated. Which is just to say we can talk about the actual world as one of the possible words. — Banno

Sure, but this is problematic due to the possibility of mistake. If we stipulate that a specific possible world represents the actual world, then we take that special status assigned to "the actual world", for granted, even though it might not be a correct representation. Therefore, the title "the actual world" requires more than simple stipulation, it requires justification.

"things, as phenomena, determine space; that is to say, they render it possible that, of all the possible predicates of space (size and relation), certain may belong to reality" (CPR). — SophistiCat

I agree with most of that. I can see that we need to say that the actual is possible - even if that is a bit awkward in some ways. It certainly beats saying that the actual is not possible.
I'm not sure I understand this sentence. But if you mean that things determine space, rather than the other way round, I'm with you.

But Banno seems to be influenced by some sort of common language intuition which makes him think that it's nonsense to say that what is actual is not possible. — Metaphysician Undercover

There's a false dilemma there. There's something wrong with saying that the actual world is possible and something wrong with saying that it is not possible. I am trying to express that by saying that the actual world is not merely possible and that it is different from all the other possible worlds in that respect.

What you propose here is just ridiculous, because one could just as easily stipulate that the world which Branson's wife did not die, is the actual world. — Metaphysician Undercover

You are missing the point. You cannot stipulate which possible world is actual. That's not a decision that we can make. We can only recognize the status of the actual world.

A god logician will understand that they can only know what it is possible to know.

You are missing the point. You cannot stipulate which possible world is actual. That's not a decision that we can make. We can only recognize the status of the actual world. — Ludwig V

yep.

There's something wrong with saying that the actual world is possible and something wrong with saying that it is not possible. — Ludwig V

That's what I said, it's categorically distinct.

You are missing the point. You cannot stipulate which possible world is actual. — Ludwig V

That's Banno's claim. Banno said we stipulate which world is the actual world. I addressed that in my last post. If one of the possible worlds is supposed to represent the actual world, this needs to be justified rather than stipulated. But then the justification will be be judged.

That is why Banno's claim that modal logic gives us a rigorous way to talk about the actual world is incorrect. To apply rigor to the way that we talk about the actual world requires strict rules on the use of descriptive language, and also for justifying the claims of "actual". But this is outside the purveyance of modal logic.

A god logician will understand that they can only know what it is possible to know. — Banno

Sure, all of us atheists will agree with that. We know that "god" itself is inherently contradictory.

Banno said we stipulate which world is the actual world. — Metaphysician Undercover

Banno said we are int he actual world. He also said that we can stipulate that we are talking about the actual world - a bit of semantics. We do not get to stipulate that we are in the actual world.

You are playing on the difference between the metaphysical truth that we are in the actual world, and the semantic truth that we can stipulate whatever possible world we want. That failure to recognise the difference between semantics and metaphysics runs right through the confusion you show here.

By definition, the actual world is the one we are in. Is that what you are asking?

Or are you asking for proof that you are in the actual world? — Banno

Right now, as I post this, I am in the actual world of TPF. As are you when you are participating in it. It is very real. It psychically exists. It can be measured by both of us by observing not only our interactions but if we were to physically meet at whatever server or computer infrastructure contains our interactions. Someone who has never heard of TPF would have no knowledge or reason to believe in this "actual" world we are both present in, without visiting it themself, or visiting the underlying location this interaction is made possible by.

Now, say if me and another member were engaging in a private message. That's, in affect, it's own world. That only the two of us would know about and you would not be privy too. Naturally, you could say it's simply a function of the larger world of TPF and furthermore beyond that, a feature of the larger physical world we could both meet.

The fact remains, in each smaller world, each participant knows only what they're able to access, leaving that larger than it unknown, as if it didn't exist. Yet it does, but only those able to access it would know that.

So again, we go back to the original question. How do you know there's not a larger world than what you're able to access?

Or are you asking for proof that you are in the actual world? What could that look like? — Banno

I'm sure you and I are in the same world, as we're two entities able to communicate within it. But that doesn't mean, for certain, there's not a larger world in which only one of us may be able to access. That would, in theory, make that hypothetical larger place the "actual" world. No different than how a private message between myself and another is a "world" or "reality" that while myself and the person I'm speaking to could access, you yourself could not access. Just as this forum is a "world" that we can both "access" but someone who does not have access to a computer nor it's physical server location would not consider an "actual" location.

Seems to me you are playing on various differing uses of "world" here. The use of "world" in modal logic is clearly set out in the formal systems that use it. It need not be the same use as that found in describing the world of TPF.

I agree with most of that. I can see that we need to say that the actual is possible - even if that is a bit awkward in some ways. — Ludwig V

Well, I did select a rather awkward quotation for my example - this is Kant, after all, so of course, of all the ways he could have expressed his thought, he did it in the awkwardest way possible (see what I did here?)

There's something wrong with saying that the actual world is possible and something wrong with saying that it is not possible. I am trying to express that by saying that the actual world is not merely possible and that it is different from all the other possible worlds in that respect — Ludwig V

I think that the difficulty here is that in ordinary speech, we are expected to make the strongest warranted assertions. There is even a word in English for failing to do that: understatement. Sometimes, understatement is used intentionally to convey more than what is being literally said, such as sarcasm or playfulness. But when an understatement is unwarranted, it can lead to misunderstanding and even offense. If, when asked what I thought about Ludwig V, I said: "well, he is not a hopeless fool," that would surely be rude and unfair, even if true in a literal sense. But if in a different context I said "Ludwig V is no fool," such an understatement would carry the opposite meaning. Ah, the vicissitudes of language!

All that is to say that the reason we don't usually say that the actual is possible (except as in my examples above) is that it goes without saying - and so it goes unsaid.

Banno said we are int he actual world. He also said that we can stipulate that we are talking about the actual world - a bit of semantics. We do not get to stipulate that we are in the actual world. — Banno

What do you mean we don't get to stipulate that we are in the actual world? You personally, have stipulated that we are in the actual world, numerous times just today.

You are playing on the difference between the metaphysical truth that we are in the actual world, and the semantic truth that we can stipulate whatever possible world we want. That failure to recognise the difference between semantics and metaphysics runs right through the confusion you show here. — Banno

If you stipulate (say) that we are in the actual world, which is an unstipulated world, and you also stipulate (say) that the actual world is one of the stipulated possible worlds, you very clearly contradict yourself.

Which do you have it to be? Are we in the actual world, or is the actual world one of the possible worlds? You cannot have both without contradiction.

What do you mean we don't get to stipulate that we are in the actual world? You personally, have stipulated that we are in the actual world, numerous times just today. — Metaphysician Undercover

:rofl:

Keep going.

Keep going. — Banno

Going where? I've laid bare your contradictions and now you say no more. Seems you can't write anything without it being contradictory, so you've shut up.

I've laid bare your contradictions — Metaphysician Undercover

You've laid bare your own confusion.

The actual world is a possible world. The actual world is the one in which we may empirically verify statements as true, as opposed to other possible worlds, where we stipulating them to be true.

The actual world is the one in which we may empirically verify statements as true, as opposed to other possible worlds, where we stipulating them to be true. — Banno

So "the actual world" is not the world we live in, (where we live, work, and play, does not consist of statements), it is a world of empirically verifiable statements. And the actual world is not one of the possible worlds which consist of stipulations rather than empirically verifiable statements. Therefore the actual world is not a possible world. Agree? Obviously, it would be a mistake to say that what is actual is also possible, because you've provided clear principles to distinguish the two, and the actual is known to be actual, and distinct from the possible.

But are your principles really clear? "We may empirically verify statements"? Are you saying that "the actual world" consists of statements which are possible to verify empirically, but are not necessarily verified empirically? If we do not actually verify the statements, how would we distinguish a statement of the actual world, from a stipulation of a possible world? Suppose I present you with two statements/stipulations, S1 "it snowed here yesterday", and S2 "it did not snow here yesterday". How would we know which one is an empirically verifiable statement of actuality, and which one is a stipulation of possibility?

Furthermore, if we do actually empirically verify the statements, then how are the "stipulations" truly "possible"? Do you see the dilemma? If we do not empirically verify S1 or S2, then we have two stipulations of possibility. If we empirically verify S1 or S2, we have a statement of actuality, but the other has been ruled as contrary to actuality, and no longer possible.

Your proposal of empirically verifiable statements sucks, as completely useless.

The issue is if, when you judge that p is true, you can also judge that it is possible that p is true. I think that this is dishonesty and contradiction because "it is possible that p is true" contradicts "p is true". This is because "p is true" means that it is not possible that p is false, whereas "it is possible that p is true" means that it is possible that p is false. Therefore contradiction. — Metaphysician Undercover

If it is possible that p is true, then this means that either p is true or p is false. So this gives us (p or ~p). But we have asserted that p is true. Therefore (p or ~p) is also true.

Your posts are becoming increasingly confused.

The “actual world” is not a special kind of world. It is simply this world—the world we inhabit. Every world can call itself “actual” from its own viewpoint. No, it doesn't "consist" of verified statements.

There's been a cold snap, and it might have snowed in Jindabyne overnight. I haven't checked the weather, so both "It snowed in Jindabyne overnight" and "It did not snow in Jindabyne overnight" are possible, so far as I know. Either is epistemically possible.

Now I've just checked, and there was no precipitation in Jindabyne overnight. So it didn't snow. It is not epistemically possible that it did snow, since we now know it didn't.

But we can consider what things would have been like had it snowed overnight in Jindabyne. The roads might be closed, the school shut, and so on. It remains metaphysically possible that it snoed there overnight.

Notice the two differing modalities, metaphysical and epistemic. Your account, as I've said before, fails to differentiate these. It makes the error of thinking that because epistemically, we know it did not snow in the actual world, it is not metaphysically possible that it might have snowed.

In more formal terms, consider to worlds w₁ and w₂ and "p"= "it snowed in Jindabyne last night", such that p is true in w₁ and false in w₂. Epistemically, prior to our checking the truth of p, we can access both w₁ and w₂ - either might be the case. After checking, we no longer have access to w₁.

But metaphysically speaking, we continue to have access to both w₁ and w₂ even after checking.

Note that in all cases the actual world is one of the possible worlds.

On your account, Meta, because it did not snow, we could consider the possibility of what things would be like if it had snowed. But this is false. We can consider what things would have been like had it snowed.

Yes, and

This is because "p is true" means that it is not possible that p is false — Metaphysician Undercover

is the source of Meta's confusion. If we apply Meta's logic to the example I just gave, then because it did not snow last night in Jindabyne, we cannot give any consideration to what may have been the case had it snowed in Jindabyne last night.

But I hope this is obviously not true. We can talk about what it would be like in Jindabyne, had it snowed, even though it did not.

But a good metaphysician will recognize the category division, and the danger of contradiction if we allow that the actual is also possible. — Metaphysician Undercover

I'm sorry, but I don't understand what you mean by "the danger of contradiction". I'm used to contradictions existing or not - contradictions as a risk are new to me.

But I hope this is obviously not true. We can talk about what it would be like in Jindabyne, had it snowed, even though it did not. — Banno

Yes, it is obviously possible to discuss the consequences of a counterfactual. But "p is true" rules out "p is false"; or that p is incompatible with not-p. It seems natural to say that, in some circumstances, that there is no possibility that p is false - not that naturalness is the final court of appeal. So I think that this needs a little more clarification. Perhaps we need to say something like before the race is run, it is possible that my horse will win and possible that it will lose, but that after my horse has won, it was possible. Alternatively, we could explain a counterfactual as positing a context in which to consider various possibilities (I would have won my bet)

It seems natural to say that, in some circumstances, that there is no possibility that p is false — Ludwig V

Seems to me that the notion of accessibility does just this.

In a world in which p is false, not-p is indeed impossible. That is within the one world. In other worlds, not-p might be true.

(That's why, as mentioned earlier, Meta's account can be made consistent if we presume that a world cannot access itself - if we reject reflexivity. But this is false in both S4 and S5.)

Perhaps we need to say something like before the race is run, it is possible that my horse will win and possible that it will lose, but that after my horse has won, it was possible. — Ludwig V

Yes: before the race is won, we can (epistemologically) access both the world in which the horse wins, and the world in which it doesn't. After the horse wins, it is no longer (epistemically) possible to access the world in which it lost. All of which is a fancy way of saying that once we know the horse wins, it is no longer possible for us to know it to have lost.

But we can still access it metaphysically - "If it had lost, I would not have been able to make the rent!"

Minor quibble. As a basically plain language person, the word metaphysically seems out of place.

metaphysically possible — Banno

Hypothetically possible, theoretically possible, epistemically possible (your term) work much better - at least for me.

As a basically plain language person, the word metaphysically seems out of place. — EricH

Yeah, I wasn't too happy with it either, but it's what is use din the literature when making this point, so I used it too. Go ahead and use your own terms.

The SEP article The Epistemology of Modality goes in to this is great detail, if you have sufficient interest. The first part gives a prety straight forward account of distinctions between metaphysical modality, logical modality, conceptual modality, epistemic modality, physical modality, technological modality and practical modality...

If it is possible that p is true, then this means that either p is true or p is false. So this gives us (p or ~p). But we have asserted that p is true. Therefore (p or ~p) is also true. — EricH

If this is supposed to be an argument for p -> ◇p (if p then possibly p), then it does not work.

Notice that (p or ~p) is a tautology: it is true regardless of the value of p. So, you might think that you could make a parallel argument for ~p -> ◇p (if p is false, then it is possible that p is true). But that is, obviously, not the case, since p could be necessarily false, and therefore not possibly true.

You can't reduce modality to classical non-modal logic. If you want a formal proof of p -> ◇p - well, this is considered to be such a basic modal intuition that it (or an equivalent principle □p -> p) is usually taken as an axiom.

Your posts are becoming increasingly confused. — Banno

That's a direct reflection of what you are telling me. You are confusing me with nonsense.

Notice the two differing modalities, metaphysical and epistemic. Your account, as I've said before, fails to differentiate these. — Banno

From everything that I've read, one's metaphysics must be consistent with one's epistemology, or else there is contradiction within the person's philosophy. So the distinction between "metaphysical" and "epistemic" does not excuse your contradiction.

Note that in all cases the actual world is one of the possible worlds. — Banno

For the reasons I explained in prior posts, this is contradictory. You provided a distinction. Possible worlds consist of stipulations, the actual world does not consist of stipulations. Therefore it is contradictory to say that the actual is one of the possible worlds. Will I have to point this out to you an infinite number of times before you accept it?

If we apply Meta's logic to the example I just gave, then because it did not snow last night in Jindabyne, we cannot give any consideration to what may have been the case had it snowed in Jindabyne last night. — Banno

Why not? What's your problem here? We could give the very same consideration to "what may have been the case if it had snowed", while still acknowledging that it is impossible that it actually did snow. Is that difficult?

If we do not know whether it snowed or not, we consider that both are "possibilities". If we know that it did not snow, then that is known as an actuality; and the alternative is known as a counterfactual. There are no possibilities with respect to this situation in that case, because what is actual is known. I think that is what already pointed out to you

I'm sorry, but I don't understand what you mean by "the danger of contradiction". I'm used to contradictions existing or not - contradictions as a risk are new to me. — Ludwig V

There is an implied contradiction, in saying that the actual is also possible. This is the one I've been explaining to Banno, who continues to refuse to acknowledge this. Check the above. I called it a "danger of contradiction" because I am still giving Banno the benefit of the doubt, to see if he can provided definitions which would establish consistency.

The point is that "actual" can be made to be one of the possibilities, but that annihilates realism. We must instill principles other than realist principles to distinguish the actual from the possible, if the actual is to be one of the possible. This is the case with model-dependent realism for example, which claims "realism" in the name, but is not realism. The glaring problem being that realism denies the priority of the possible, therefore the actual cannot yield logical priority to the possible, which is required to conceive of the actual as one of the possible. The actual, real, must be distinct from, and logically prior to, the possible, for true realism.

Banno's problem is that he does not want to relinquish his realist ontology, but he wants at the same time to accept the priority of modal logic. Now he is starting to propose a division, a boundary, between metaphysical principles and epistemic principles, so he can hide the contradictory principles, one on each side of that boundary, thereby having an epistemology which is inconsistent with his metaphysics. "The actual world" means something different in Banno's metaphysics, from what it means in his epistemology.

You can't reduce modality to classical non-modal logic. — SophistiCat

Yep. It's a curio.

p→◇p is invalid without reflexivity.

For the reasons I explained in prior posts, this is contradictory. — Metaphysician Undercover

And your reasoning has been repeatedly shown to be in error.