I haven't read much about modal logic, but as most people here have agreed, the premise is unsound. Here are a couple examples of modal arguments.
Let W be the set of possible worlds that might exist after Feb 3, 2022 (i.e. possible futures). If it a person "Bob" is necessarily dead in one of those possible worlds, then he necessarily is dead in all of them. This is absolutely correct logic.
How is it correct? It centers around what "necessarily dead" means. If we assume a world where the past is unchangeable, then if it were found that "Bob" has been dead since 2015, then he is necessarily dead in that world, as opposed to accidentally dead (if he died tomorrow). He necessarily must be dead in all possible worlds in set W.
Let us change W to be the set of possible worlds that might have existed from the moment of the Big Bang. We assume there are some sort of rules which are common to all elements in W, which all cause this Big Bang. If we find that there is one world in W where God necessarily exists, then necessarily God must exist in all elements of W.
Again, how would you determine what necessarily means? It would have to mean that God was required to exist, meaning that God existed prior to the Big Bang, which means that God exists in all post-Big-Bang worlds.
Stating the premise is assuming the conclusion. The premise is bad, and cannot be proven. We are in one of these worlds in W, and we can't even find evidence of a God, and definitely can't determine necessity. How would any of these worlds be able to do the same, given that they arose from whatever same rules that our Big Bang started from?
The premise assumes that there exists an element of Set W that has a certain property. But, there doesn't have to be any such element.
Let W be the set of possible worlds that might exist after Feb 3, 2022 (i.e. possible futures). If it a person "Bob" is necessarily dead in one of those possible worlds, then he necessarily is dead in all of them. This is absolutely correct logic.
How is it correct? It centers around what "necessarily dead" means. If we assume a world where the past is unchangeable, then if it were found that "Bob" has been dead since 2015, then he is necessarily dead in that world, as opposed to accidentally dead (if he died tomorrow). He necessarily must be dead in all possible worlds in set W.
Let us change W to be the set of possible worlds that might have existed from the moment of the Big Bang. We assume there are some sort of rules which are common to all elements in W, which all cause this Big Bang. If we find that there is one world in W where God necessarily exists, then necessarily God must exist in all elements of W.
Again, how would you determine what necessarily means? It would have to mean that God was required to exist, meaning that God existed prior to the Big Bang, which means that God exists in all post-Big-Bang worlds.
Stating the premise is assuming the conclusion. The premise is bad, and cannot be proven. We are in one of these worlds in W, and we can't even find evidence of a God, and definitely can't determine necessity. How would any of these worlds be able to do the same, given that they arose from whatever same rules that our Big Bang started from?
The premise assumes that there exists an element of Set W that has a certain property. But, there doesn't have to be any such element.
