And now we are in a position (at last) to think with some degree of clarity about the subject of this book. When we speak of “mystery” from now on, we are speaking of a revelational mystery that is dimensional in character—that is, of a mystery that is impenetrable even after it is revealed, not by virtue of its quantitative magnitude, nor by virtue of its existential uniqueness, but by virtue of an unimaginable depth or density that transcends our rational capacities and all of our other capacities