Elsewhere, in light of the idea that understanding is not a species of knowledge but an epistemic genus parallel to knowledge, and then in terms of an understanding logic, I asked whether knowledge of analytic truth might be framed as uS → kS, i.e. some S is analytic if understanding it is sufficient in order to knowing it. The thesis that all existential S are synthetic could then be framed as something like ~(u∃S → k∃S).
The Wikipedia article on the ontological argument says of Aquinas' position on this subject:
He suggested that people cannot know the nature of God and, therefore, cannot conceive of God in the way Anselm proposed. The ontological argument would be meaningful only to someone who understands the essence of God completely.
However, Aquinas also said that God is subsistent being itself. Now Ayn Rand (in)famously axiomatized the assertion, "Existence exists." So, firstly: is, "Existence exists," analytic or synthetic (if "true" at all)? But more importantly: is it possible, in understanding existence itself, to then know whether certain things do or do not, as such, exist? As if they were "encoded" into the sheer form of existence, then. Then we might say, not that existence is analytic of God, but that God is analytic of existence (insofar as the creation/uncreation function would be a fundamental existential type).
In other words, does Aquinas implicitly advance his own ontological argument, notwithstanding his claim to disavow such an argument scheme?
EDIT: As a historical aside, consider that according to Ayn Rand, all truths are analytic because the analytic-synthetic distinction is a delusion (and unlike Quine, she does not seem to rule in favor of universally synthetic truth). Ergo, Rand's essential philosophical thesis, and an unusual one at that (not to recommend it!), is that existence truths are also analytic, and indeed, "Existence exists," would be analytically true. Modulo a reliance on principles for resolving contradictions, this thesis becomes the idea that resolving contradictions is the crux of our knowledge of what exists.
In other words, in Rand's system, foundationalism and coherentism effectively collapse into each other.