Illustrating the burden of proof - pay me!

[GrandizerII]

And an atheist critic will say, that inserting the contingent/non-contingent qualifier up front allows the theist to conclude that there is at least one non-contingent cause. Maybe. What is the alterative? Everything is contingent on everyting else in a circular reference? Or nothing at all is contingent? Those who object to that distinction seem not to object to the notion that some things supervene on an ultimate physical ground that is fundamental. Sound the same conceptually.

They are similar conceptually, but my issue is that though both propose a fundamental ground, theism makes much more speculative assumptions to do so, and seems to end up proposing a much more complicated fundamental ground than that which it is attempting to replace in the known universe. Ie in a nutshell, theism seems to look at the circular contigency evident in the universe, unable to accept that any part of it could be fundamental, even in principle, and instead asks 'how did any of this come to be, from nothing?', then with complicated logic (eg the Five Ways etc) it proposes a solution that by the nature of parts of its definition, entails that the solution is exempt from those sorts of questions (ie via the concepts of necessary/non-contingent), but does so at the expense of proposing a new fundamental thing of the universe/reality... a complex/multi-faceted all-powerful being... that is far more complicated than that which it was invoked to explain, and thus far less likely to just happen to exist for all eternity 'just because' or as Belacqua said Aquinas would put it '[for] no reason'.

So from my point of view, all it does is replace one (or many) plausible and scientifically addressable fundamentals, as yet discovered or not, in the known universe, with one speculative and unfalsifiable centralised fundamental, at the gain of some mental reassurance/i's dotted and t's crossed in the form of the theological logic, but without ultimately addressing the underlying question of how something rather than nothing exists or comes to be, because it cannot answer the question as pertaining to itself. And to the extent that it is claimed that it doesn't need to (ie by definition of necessary/non-contigent) that's ultimately what I was asking you about... whether a) that truly closes the book for you on that question, in the case that you accept that the definition is a complete answer to God's existence requiring no further explanation, or to put it as boldly as Aquinas would (to again quote Belacqua surmising Aquinas) 'there is no reason for God's existence, because God is not contingent', or b) that you still have such questions but out of necessity/practicality accept you can't answer them. But in either case seemingly accepting God as a brute fact/fundamental. I'm not asking for an answer again if you don't want to give it... I appreciate your answer from before, which seemed to be neither of these... but just restating/clarifying my thinking around this in the context of this new post of yours.

Epistemically, we're bound to hit a dead point when we're trying to figure out why something rather than nothing or why this rather than that? As per Munchhausen's trilemma, you're either going to posit a brute fact as the ending point, go with a circular explanation, or appeal to an infinite regress of sorts. There's no way around that. For theists generally, having God as a brute fact is how they ultimately make sense of everything in existence, only because intuitively, God (as the ground of being) is seen as metaphysically necessary, while an arbitrary physical universe is not intuitively seen as such. It all comes down to intuition at the end. We can't say for sure this universe is contingent or necessary, but it feels like it is contingent because we can imagine a slightly different universe instead in place of the actual universe. To make the view that physical reality (whether comprising only this universe or multiple universes) is not contingent far more intuitive, one would probably have to go with some extreme view of modality. For example, necessitarianism (this world/universe exists as is because it exists necessarily as is) or a more radical form of it, called modal realism (all possible worlds exist and exist necessarily).

Or you can ditch the PSR and just say the universe is contingent but it just is.

Of course, theists also have to grapple with issues regarding God being necessary while everything else in existence is not. Modal collapse arguments, in their various forms, are examples to counter that view.