Well, "the metaphysical" needs to actually be there, before it can show us any shortcomings of "scientific naturalism".
How exactly does someone observe the "unobservable"? How could one come to confidently believe in a realm built up out of "unempirical" content?
If anyone can satisfactorily answer these questions, chances are they have done science, and discovered that the unempirical content everyone was talking about was scientifically describable after all, unique from other science only in its being particularly difficult to apprehend.
Until we get there, this unempirical component of consciousness being posited shares common heritage with the Luminiferous aether, the life-force, hollow earth theory, mythic gods of natural forces and any number of premature theories which hover in the closing gaps of indeterminacy before a science comes along to explain them.
Keep in mind though, a large part of modern science is a monism - it tries to explain everything starting from a single principle.
I'm not saying that's right or wrong, I'm just pointing it out. A monism works beautifully, as long as its basic assumptions are true. Unfortunately, the converse is true - a monism cannot detect whether its axioms are true or not. The more it keeps digging, the more it appears to confirm itself.
It is quite possible that the fundamental assumptions of materialist science are true. It's just that, if they are not, chances are the system will never detect its own incompletitude.
... this unempirical component of consciousness being posited shares common heritage with...
Past performance is no indicator of future results, and one theory's individual case of validity has no bearing on the validity of the next one to be tested. I do like how you tried to dismiss it by grouping it in with the other theories, but as we both just examined, that is faulty logic and merely supposition.
How exactly does someone observe the "unobservable"? How could one come to confidently believe in a realm built up out of "unempirical" content?
If anyone can satisfactorily answer these questions, chances are they have done science, and discovered that the unempirical content everyone was talking about was scientifically describable after all, unique from other science only in its being particularly difficult to apprehend.
Until we get there, this unempirical component of consciousness being posited shares common heritage with the Luminiferous aether, the life-force, hollow earth theory, mythic gods of natural forces and any number of premature theories which hover in the closing gaps of indeterminacy before a science comes along to explain them.