Necessary Thing

[Ignorant]

... If naturalism and determinism are both true, then the universe itself would be necessary in that it could not avoid being the way it is...

I certainly agree with that. But, as is evident from your clarification in the final clause, that is an equivocal use of necessary (as opposed to necessary in the sense of non-contingent).

My more general suspicion is that our brains are not equipped to have realistic intuitions about such things. Our notions of cause and effect appear to be modeled on physical interactions and are not geared for making sense of things like quantum entanglement. Failing a way to step outside of myself, my intuition is that all things are contingent.

What do you mean by intuition and why do you think that is an important aspect?

How that works its way out wrt something coming from nothing and eternal pasts, I don't know. I think we may never know.

Which is why I mentioned that your definition of contingency, though not "wrong", may be too narrowly defined in a temporal sense. Do you think it is possible to consider present conditions/contingencies for a particular thing which is currently existing? What are the conditions (if any) for its continuing existence?

In other words, there are certainly the historical/cosmological conditions/contingencies for the present existence of carbon atoms which must have been fulfilled for carbon to exist (e.g. the development of the universe, formation of stars, explosions of stars, etc.). Whether or not that historical sequence of conditioned events is deterministic has no relevance for the presence or absence of conditions for today's carbon atoms. Rather than tracing a chain of conditions/contingencies backwards through time, can we not consider tracing a different and present chain of conditions "downward" through "what" it is (e.g. an animal is conditional upon functional organs, which are conditional upon functional cells, which are conditional upon certain organelles, which are conditional upon molecules, which are conditional upon... etc.)?