The Inner Ring, by C. S. Lewis
". . . But you have met the phenomenon of an Inner Ring. You discovered one in your house at school before the end of the first term. And when you had climbed up to somewhere near it by the end of your second year, perhaps you discovered that within the Ring there was a Ring yet more inner, which in its turn was the fringe of the great school Ring to which the house Rings were only satellites. It is even possible that the School Ring was almost in touch with a Masters' Ring. You were beginning, in fact, to pierce through the skins of the onion. And here, too, at your university-shall I be wrong in assuming that at this very moment, invisible to me, there are several rings - independent systems or concentric rings-present in this room? And I can assure you that in whatever hospital, inn of court, diocese, school, business, or college you arrive after going down, you will find the Rings-what Tolstoy calls the second or unwritten systems."