The proposition before us is whether it is possible to conceive of an entity which cannot fail to exist. Vera said in post #7 that all we need to do to show necessary existence is not conceivable is to “consider two different possible worlds which have nothing in common.” To illustrate he offers his reduction hypothetical (thought experiment) in #48 which results in a single proton world and a single neutron world. He then concludes: “So, we have two, physically possible worlds, without any intersection. Ergo: “no necessary being”.
Granting all the assumptions that go with possible worlds (which I don’t pretend to understand), this does seem to be a disproof of necessary existence.
I am glad you see it. Perplexity did not. (Maybe he confuses “hypotheses” with “axioms”.) Possible world is simply an arbitrary state of affairs of ontological entities, which does not contain logically nonsensical / contradictory entities. However, it is important to stress that “concepts, ideas, abstractions, etc…” are NOT ontological entities. Ontological entities are stones, gods, leprechauns, “things”… Love (for example) or “truth” are not ontological entities.
However, I don’t trust this conclusion on other grounds. First, thanks to Parmenides, we know that something or other must exist. Granted, it doesn’t have to be one entity.
You got it right. But you don’t need to refer to anyone. If, what you say is correct, referring to outside source is not necessary. If, what you say is incorrect, referring to outside source does not help. “Nothing” is a concept, not an ontological entity. It only exists as an abstraction, not as “something”. To say “nothing exists” (where “nothing” is understood as an “ontological something”) is nonsense.
This is extremely important.
Necessary existence could be exemplified by an unending succession of contingent beings, the whole of which cannot fail to exist. But I don’t think this precludes one entity (or multiple entities) which cannot fail to exist.
You have to be careful. “Contingent” existence does not mean that entity “X” is logically or physically contingent on entity “Y”. It only means that entity “X” is present in some world “W1”, but not present in another world “W2”. For example, the existence of this post is physically “contingent” on my existence (even though my continued existence is not necessary). Once it is posted, it will continue to exist as long as the server exists, and as long as the moderators allow it to persist. In the unlucky event when the Sun goes nova, the post will disappear. We can also conceive of a different possible world, when the same post exists, but was written by someone else.
Necessary existence only means that an entity “X” exists in all different possible worlds. The usual,
colloquial meaning of “it is necessary FOR something” does not apply. There are many “unfortunate” choices in the language. In mathematics, the concept of “irrational numbers” has nothing to do with rationality, it only has to do with “ratio”, the division of two numbers.
Doesn’t it assume that in our possible world constructing we can flip the T/F or exist/doesn’t exist switch on any element of the actual world (as long as we don’t end up with something nonsensical)?
Yes it does, and it has nothing to do with logical positivism, explicit or implicit.