Oh really, and at what point does it not involve you "rationalizing" about it in the space between your ears? In fact, if there was no "rational" mind in the first place, to "rationalize" about the existence of anything, then who cares? The ability to rationalize must be preeminent, otherwise there is nothing to discuss. By the way, I think we all can agree (through our ability to rationalize that is) that a physical reality does exist. However, beyond our ability to rationalize, we may not be able to prove it.