Suppose a world Y is not actual. Why? There has to be a reason why that is.
— TheMadFool
There is a possible world in which my cat is ginger.
In the actual world, he is black.
Now the reason, if you need one, that the possible world in which my cat is ginger is not the actual world is that my cat is black. — Banno
Nuh. "Actual" is an indexical. Like left and right. The folk in each possible world think they are in the actual world.
Add that "Necessarily" is just "In all possible worlds", and hopefully you will see why your proposition is ill-formed. — Banno
Nuh. Jack - a rigid designator - might have been ginger. That sentence makes sense. It's exactly the sort of thing modal logic is intended to deal with.Your cat could not be ginger in any possible world, because it would not be the same cat. — Janus
You're assuming that this (the) world is the only actual world. — TheMadFool
The word "actual" as an indexical is not, I think, important. — TheMadFool
Actually I explicitly said that the folk in each possible world think their world is the actual world.
But yes, there is only one actual world, within the structure of modal logic. — Banno
If you think that, you've missed the point. — Banno
How can modal logic (about possibilities and necessities) ever even claim there is only one actual world. — TheMadFool
Question for you: Is world Z impossible or is world Z possible? — TheMadFool
How would you be able to tell? — TheMadFool
Might be either. You haven't yet specified. — Banno
Nuh. Jack - a rigid designator - might have been ginger. That sentence makes sense. It's exactly the sort of thing modal logic is intended to deal with.
Jack's identity is maintained across possible worlds. — Banno
I suppose we might specify a possible world such that the folk therein believe their world is not the actual world.
A world of mad fools? — Banno
:up:↪TheMadFool The problem with this argument is that the idea of God is not that he could exist in some possible world, but that insofar he could be said to exist in any world then he necessarily exists in every possible world. But that, being a mere idea, doesn't tell us anything about God actually existing. This argument fails in the same way as the Ontological Argument. — Janus
What's the problem? — Banno
1. World X is possible & World X is not actual (you would agree)
2. World X is impossible & World X is not actual (obvious)
I give you world Z which is not actual. That is to say,
3. World Z is not actual.
Question for you: Is world Z impossible or is world Z possible?
How would you be able to tell? — TheMadFool
What you suggest is that there is an atomic world where each configuration of a grain of sand in every possible desert is actualised in possible worlds. Clearly not mate. — Varde
Nuh. The "proof" is just you specifying that X is the actual world or that it isn't.1. If world X is not actual then there's a proof why world X is not actual. — TheMadFool
Nuh. The "proof" is just you specifying that X is not the actual world or that it is. But also, the phrase "Necessarily word X is not actual" is ill-formed. It comes out as something like "in all possible worlds world X is not actual"; which presumably is just "World X is impossible".2. If there's a proof that world X is not actual then necessarily world X is not actual. — TheMadFool
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