So by extension the supernatural is the absence of the natural? That's it? It's equivalent to nothing?
Analogies aren't perfect unfortunately. It was just to show that it isn't uncommon to define something in regards to something else.
I certainly think that is a better start since it is consistent with the structure of the word (super = above). "Outside of nature" might be better described as "perinatural", or perhaps "paranatural" which is close to paranormal.
THe structure of the word was my first line of thinking when coming with 'outside of nature'
But again, we have some of the same problems. No one describes the geography of Europe as "outside of America". At some point there needs to be a positive description, a description of what actually constitutes the supernatural.
Your analogy doesn't really describe the situation here. We can go outside of america into europe to see what it is and describe this way. This cannot be done in the case of nature, and so it limits how we can define it.
A more suitable analogy would be if we were all locked up in a house with no contact with the exterior world but a little tiny hole in the ceiling. Everyday, light would start to come through the hole and follow a precise trajectory across the room and disappear. One day, the most crazy out of us would say that this light comes from a light source that is actually outside the house and who is circling us. This would explain it's trajectory. How useful would it be for the others to say:
- well, where is this light source anyway ?
- I can't tell for sure, but I can say that it is outside the house.
- Oh but this doesn't tell us where it is. It simply tells us where it is not. That's not an answer.
- Well I cannot tell you anymore then this, because this is all I can say from our point of view.
Of course, his answer isn't the best one possible. But it is the only one he can give, and in fact it is sufficient enough for everybody to understand what he means and so although it isn't optimal, it still is accurate enough.