Independently, by each observer. Note we are dealing with a strict dichotomy. We are also dealing with a huge lack of direct, experiential knowledge as to what ultimately drives the universe.
If God is natural, then what is supernatural? There is a problem with defining natural as only that which can be understood by human reason, at least from an empirical standpoint. The problem is that we have no way of determining whether our definition of natural coincides with objective reality.
In addition to that, the dichotomy invites a tautology: We end up saying science can only deal with only natural phenomena while at the same time defining "natural" as only that which science can apprehend. How can science know for sure it is not the "nature" of things to fly apart without reason and disintegrate into nothing intelligible?
You have a method to determine opinion and what some one does not know or can't be observed?