Phil at Bad Astronomy opined (and it is a common opinion) that the supernatural is incoherent:

If you posit some thing that has no perceivable or measurable effect, then it may as well not exist. And as soon as you claim it does have an effect — it can be seen, heard, recorded, felt — then it must be in some way testable, and therefore subject to science.

Joshua was not so sure about this. The supernatural could, perhaps, interact observably with the universe at some times but not at others. Under normal circumstances the normal laws apply, under others, supernatural stuff happens. Chad weighed in on that.. More..