"The invisible and the non-existent look very much alike." John Stuart Mill
I'm having a very interesting discussion with David over at Sago Boulevard about the word "supernatural." My argument is that it is a word that religious and superstitious people use to dodge the evidence that what they believe in doesn't exist.
Let's start with a basic definition. Nature is, according to the relevent definition in Merriam Webster's Online Dictionary, "the external world in its entirety." That's pretty much how I would define it as well. Supernatural, on the other hand, means (1) "of or relating to an order of existence beyond the visible observable universe; especially : of or relating to God or a god, demigod, spirit, or devil" or (2) "departing from what is usual or normal especially so as to appear to transcend the laws of nature b : attributed to an invisible agent (as a ghost or spirit.)"
We can toss out the second definition as irrelevant, because it's talking about appearences and attributions. The first I don't quite agree with, since nobody would call a galaxy so far away that we couldn't observe it "supernatural," although such a galaxy would fit this definition. So what do religious/superstitious people really mean by "supernatural?"
Maybe they mean "of or relating to an order of existence beyond the visible observable (even in theory) universe." This takes care of the parts of the universe that are too far away.
But if we carefully study even this revised definition, something will strike us. The word "beyond." "Beyond," according to m-w Online, means either (1) "on or to the farther side of : at a greater distance than," (2) "a : out of the reach or sphere of b : in a degree or amount surpassing c : out of the comprehension of," or (3) "in addition to : BESIDES."
Well, we've already ruled out 1 and 2a with our distant galaxy example. It seems like they must mean "beyond" in the sense of 2c or 3. Let's take them one at a time.
2c) Let's say that supernatural means "of or relating to an order of existence [out of [our] comprehension of] the visible observable (even in theory) universe." What does this mean? If the supernatural exists, even if we couldn't comprehend it, we should at least be able to observe it. Since when is observation limited by comprehension? I can observe a kid acting out "beyond" reality, meaning I can't comprehend how a human being could behave like that, but I'm still observing it. I can't comprehend in some senses the Big Bang, but I can still observe (indirectly) that it happened. I don't think we can use this sense of "beyond" to make "supernatural" mean anything.
3) Perhaps supernatural means "of or relating to an order of existence [in addition to or besides] the visible observable (even in theory) universe." This implies that supernatural beings reside someplace other than the universe. However, time and space are bound by the universe, so there is no "outside" the universe (or "outside" time.) Some scientists do hypothesise a "multiverse," where reality is made up of many universes, but it's a heavily criticed line of reasoning, and proponents of the "supernatural" surely don't mean "something that's natural, just in a different universe," anyway.
I'm left with the conclusion that "supernatural" doesn't mean anything more than "non-existent," or perhaps "fictional." In one sense, Huckleberry Finn could be said to exist, but I don't think that's what theists mean when they talk about the supernatural. "Supernatural" is a term applied to that which doesn't exist in an effort to make it seem like it does.
There's one more point I'd like to make, and that is that scientific claims are always extraordinarily detailed and concrete while religious ones tend to be vague and abstract. I think this is the case because detailed and concrete religious claims were too easily to disprove and the faithful have adapted. Now you'll very rarely see a falsifiable religious claim. (People raise the same objections about string theory, an area of exploration that many claim is not scientific because it's not falsifiable.)