@magitweeter @Radical_EgoCom @stinky There's no existence claim that refers to nontangible objects that can be proved or disproved. But no, that's no reason in itself to be agnostic about them.
I'd argue, e.g., that the claim that God exists and the claim that quarks exist have the same epistemic status. Neither object is directly perceptible. All evidence for either is circumstantial.
But that's not a reason to be agnostic about the existence claims. People believe or disbelieve such claims based on the worldview they're operating under. If the existence of a intangible object contributes to the functionalit's of the worldview it exists. If its existence detracts it doesn't. If it's neutral then agnosticism is an option.
Do you think it's possible to prove an existence claim outside of mathematics, where those words have merely technical meanings? Can you give an example of such a proof?