I do not want to get into a religious discussion. The question is an abstract one, not directed at any belief system. With that prologue: is it theoretically possible to give a rigorous and coherent definition of "supernatural" that would allow an observable event to be supernatural, independent of humans' knowledge of physical laws? That is, if one defines the set of supernatural events as either distinct from, or a superset of, the set of natural events, then this begs the question, as one now needs a definition of natural events. (The question as to whether the set of supernatural events is the empty set or not is not the question here: one first needs a definition of supernatural before one could pose that question.) If one defines natural as all that is observable (not necessarily by humans: in the same way that the laws of relativity are posed in terms of observers, or quantum physics uses observables....) I wish to exclude the trivial definition that, for example, allows lightning to be supernatural to ancient Greeks but not to Benjamin Franklin, etc. , so the final definition need not allow humans at any point to be able to distinguish a natural from a supernatural event.