Very good posts in this thread (it's my policy to ignore mark's posts).
The one thing I disagree with is the way Loudmouth defines nature, i.e. "our observable reality". The supernatural could be observed and still be considered supernatural.
I posted an explanation of my view in another thread in General Apologetics (
http://www.christianforums.com/t2565037-natural-vs-supernatural.html), so I'll just cut 'n paste it here. Of particular interest the second-last paragraph, which addresses the use of naturalism in the scientific method.
"I think there is a meaningful definition of the supernatural, but it's a relative definition rather than an objective one.
The mistake most people make is that they see the natural/physical and the supernatural/spiritual as two different realms, or dimensions or states of being or whatever. The problem with this, as some of the posts in this thread show, is that the distinction between the two realms becomes confusing (and pointless) when the supernatural has an effect of any kind on the natural. But the truth is that the only coherent way to look at this dichotomy is to abolish the dichotomy entirely: There's only one reality, which is only limited by what exists in this universe and beyond, if there is something beyond our universe.
Accepting that there is only one reality, how do you define the supernatural meaningfully? I think it has to do with the detection of patterns and the understanding thereof. I've found that whenever "natural" is used in a phrase that isn't mystical gibberish, it essentially means, "That which is understood or understandable"; the supernatural would therefore be defined as "That which is inherently beyond our understanding". I don't have a step-by-step reasoning to demonstrate this, but I've yet to come accross a context where reading "natural" and "supernatural" as the above definitions doesn't make perfect sense. Try it (and prove me wrong if you can)!
What this means is that a miracle, a supernatural event, could happen right here on Earth. It would be an event which is impossible to understand; everyone would know it happened, but no one could ever, ever explain how it happened. The same goes for ghosts: They could be all around us, they could interact with us and with objects and everything, we could observe and study them all we like, but we couldn't say what they're made of, how they can interact with us, etc.
On the other hand, what would appear at first to be supernatural (beyond our understanding) could turn out to be explainable (and therefore natural). Ghosts could be made of some new kind of elementy particles, we'd be able to predict how their presence affects normal matter, etc.
This leads to the conclusion that, as michabo implied, it is impossible to know if a phenomenon is truly supernatural. No matter how many years humanity has tried and failed to explain something, there will always be the possibility that we will one day make sense of it.
It's also possible that something which is inherently beyond human understanding would not be inhenrently beyond the understanding of a super-intelligent alien race (or really advanced AI, or genetically modified humans, take your pick). These aliens could then show us their ability to predict a supposedly supernatural phenomenon, and we'd have to admit that it is indeed natural.
This is what I mean by "a relative definition".
The only things that are objectively supernatural are things for which we have absolutely no evidence, and which by their very definition cannot be detected in any way, directly or indirectly, since it's impossible to understand something when you have absolutely no data to work with. Something like mass-less, invisible, immaterial magical imps who are so shy they never leave a single trace of their existence. But then, those imps would also be completely irrelevant, and therefore superfluous. Objectively supernatural things and beings can therefore be classified as non-existant.
By the way, I don't think even the deist God is objectively supernatural, since it (according to that belief) might have left evidence of its existence within the universe.
Clearly, an interventionist God like the Christian one isn't objectively supernatural (although the likelyhood that a being so incredibly intelligent could one day be understood by the beings he created is very, very small).
One last thing I want to clarify: This definition of the supernatural is very useful to give an adequate definition of science and the scientific method.
Since the goal of science is to understand the universe, it is obvious that scientists must assume a phenomenon can be understood if they're going to try and explain it. This is what scientists call methodological naturalism: One assumes the universe is natural (understandable) so that one can set about understanding it. This is why supernaturalist "theories" such as intelligent design are intrinsically flawed: They "explain" phenomena by appealing to something which is inherently beyond our understanding*, which halts the process. As I've said in another thread**, if our goal is to understand the universe, each new explanation must allow the question, "Now that we've explained this, how do we explain the explanation?" Any other kind of theory is fundamentally anti-scientific (and, I would argue, anti-progress, anti-thought, and profoundly destructive).
To conclude: The definition of what I've called objective supernaturalism is indeed ultimately meaningless and useless, but relative supernaturalism can be used meaningfully (although the supernatural itself is methodologically useless).
*I've said above that God (the creator of the universe), might be natural (no matter how unlikely it is), so this point may appear to be flawed. However, IDists always assume the Designer is supernatural, and never try to explain how he created proto-life, the universe, or whatever, which amounts to defining the Designer as objectively supernatural.
** Post #5 in this thread:
http://www.christianforums.com/t2564...th-theism.html "
