What if we were to discover that magnetism is actually supernatural?
Using this hypothetical, I come to the conclusion that "supernatural" is just not a meaningful word, at least in a scientific context. Magnetism might turn out to "really" be a manifestation of all sorts of fascinating phenomena, such as electricity or the weak nuclear force (both of which it is, in fact, closely related to). It could even be a manifestation of a natural phenomenon our current scientific understanding wouldn't lead us to expect — like biological life! But for it to be "really" supernatural seems incoherent.
The supernatural is usually defined in some sense whereby it is "outside science", but nonetheless has empirically detectable effects; for example, psychics generally claim to have "supernatural" powers which can, if present, be detected with Zener cards and such. But I would contend that there is nothing inherently supernatural about extra-sensory perception. Our world could be such that all or certain brains were capable of taking in "non-sensory" information from other brains; it just so happens that test after test suggests that that's not the sort of world we inhabit.
Likewise for life after death. We might all agree that "ghosts are supernatural", but what if, a hundred years from now, ghosts become a known, scientifically describable phenomenon? Would their supernaturalness… poof away?
a certain Nickelodeon show, "real" monsters couldn't exist. The way kids and adults talked about "monsters", they seemed to be, by definition, creatures whose existence was always in question. I came to see "Do you believe in monsters?" as a stupid question. Do sharks count as monsters? What about tyrannosaurs? Or does the word only apply to unseen, unknown bumps in the night?
I realized that either my closet did contain a "bogeyman" or it didn't, and the only thing that made the bogeyman "scary" was that fuzzy boundary between the two. If a professional monsterologist were to come to my room, bring out his monster-detector, and say, "Here's what a bogeyman looks like," it just wouldn't be scary anymore. It would be something we could all deal with. It wouldn't even be a monster anymore. (So dies the field of monsterology before it is born.)
Perhaps a similar principle applies with other supernatural ideas. If ghosts existed in a "scientifically obvious" way, they wouldn't be the stuff of horror films — and if angels were dependably "there", they would, paradoxically, be less comforting. No friend is as reassuring as an imaginary one.
Of course, certain known, partially described phenomena are in fact asserted by some to be "really" supernatural: namely, the mind, the weirdness of quantum events, and the fact that things even exist in the first place. I don't have counter-arguments to each available here, apart from what I've already spent this post talking about…
If dualism is "true", then that should be scientifically knowable, and if it's not knowable, there's little point talking about it. Lab physicists manage not to become mystics, despite spending their days dealing with phenomena that do all kinds of mysterious things. Quantum findings have certainly managed to fuel mysticism, but somehow, they're still not enough to make the scientists discovering the mysteries to throw up our hands and say, "It's magic! Magic is the explanation!" Science perserveres.
Isn't science amazing? It's almost, well… transcendent.