I think the term “supernatural” is incoherent. It has no real meaning.
First let’s look at common citations of the purported “supernatural”. As a random example, consider ghosts. Let’s say it is conclusively proven that apparitions with the visual and behavioral likeness of departed humans in fact lurk about the earth. Does this prove the supernatural exists? No. It proves the natural world is more bizarre than we thought. Our eyes (or brains) that we see stuff with.. are natural, made of stuff. Atoms. Ghost-stuff (whatever it is) perceived by humans and most probably machines, cameras etc.., is therefore something which interacts with atoms in our retinas or perhaps prefrontal cortex. That makes it quite natural, made of either energy or matter which can interact with other matter or energy.
Next up God. God has the same sort of problem. If he interacts with regular ol’ matter and energy.. he’s just an unusual form of matter and energy him/her/itself. Supernatural would mean separate from the natural.. but any creator god would have to be basically intrinsically linked to all matter and energy. Not very distinct or separate.. decidedly “unsuper”.
Now the philosopher replies with less pedestrian magical-thinking: Well, a second universe a “supernatural” one exists parallel to our own, and never do the two intersect. The first question is, who would care? but snarkyness aside, the idea is still incoherent. What does it mean to be “parallel” to something which does not have physical properties? Parallel/alternate/flipside are all terms that describe physical dimensions and relative locations. You can not be near something that lacks the basic physical properties of the universe you inhabit because “near” would be a nonsense phrase.
re: tautology- In philosophy or science you have to take whatever your most fundamental ideas are as axiomatic. Even if we proved conclusively the naturalistic approach is necessarily correct the new question would simply be “what’s the proof of the proof..” and so on and so on. We arn’t just philosophers, we’re pragmatic critters who need to solve real problems. We have picked the approach that is best at solving real mysteries and problems and advancing our understanding. Will someone come and ask now, do computers really exist? After all the invention is based on the absurd tautology that electrons will keep flowing for the stupid reason they’ve been doing it for billions of years? Should we stop using electonics.. ya know, just in case? After all.. we could be wrong!
Is this really significant or useful discourse? is this what philosophy is about? What a freakin’ waste of time. Get a job, hippy! /rant