Two Notions of Necessity and the Modal Ontological Arguments that Conflate Them
There are two notions of necessity floating around that easily get conflated: (i) exists in all possible worlds, and (ii) can't not exist. But (ii) can't be captured by (i); (ii) is more fine-grained than (i). Indeed, it's epistemically possible that a being is necessary in sense (i), but not in sense (ii). To see this, say that a world stub is some initial temporal segment of a possible world (whether beginningless or not). Now consider that it it's epistemically possible for a god (an uncreated, metaphysically independent being) G to exist in the world stub of every possible world, and yet go out of existence at some time downstream of the world stub of at least one -- but perhaps many, and perhaps even every -- possible world (say it commits suicide due to eternal boredom, or it's annihilated by some other being downstream of one or more world stubs). It's therefore epistemically possible for G to be necessary in sense (i), but not in sense (ii). This has ...