5 upvotes, 1 direct replies (showing 1)
Nothing I say here is without controversy, but this is a common way of thinking
"Massive bodies curve space-time" is a nomologically necessary statement, but it is neither metaphysically nor logically necessary.
All the worlds with our laws of nature are ones where massive bodies curve space-time.
It's not metaphysically necessary because the laws could have been different and it is not logically necessary because denying that massive bodies curve space is not a logical contradiction.
"Eminem is Marshall Mathers" is metaphysically necessary, but not logically necessary.
Eminem and Marshall Mather are just two names for a single object. Things are identical to themselves in all possible worlds.
It's not logically necessary because logically the statement is just A=B. So, logically there is no contradiction in denying it. the problem comes from the nature of the object referred to by the statement, not the logic of the statement itself.
"A=A" is logically necessary. Just by its form regardless of its content it will be true and will be true in any possible world.
The Rough Idea:
Nomologically necessary ~ true in all the possible worlds with our physical laws
Metaphysically necessary ~ true in all possible worlds due to the "rules" about how things exist at all in any way with any laws of nature
Logically necessary ~ true in all possible worlds because of the logical rules and the purely logical or formal features of the statement
Comment by [deleted] at 28/11/2020 at 05:55 UTC
1 upvotes, 1 direct replies
Ok, if I’m understanding this correctly, the ontology propositions, or in some cases even how the propositions are defined is what makes something metaphysically necessary, but it isn’t logically necessary because denying it doesn’t leave you with a blatant logical contradiction?