A sibyl, questioned about Marozia's fate, said. "I see two cities: one of the rat, one of the swallow."
This was the interpretation of the oracle: today Marozia is a city where all run through leaden passages like packs of rats who tear from one another's teeth of the most voracious ones; but a new century is about to begin in which all the inhabitants of Marozia will fly like swallows in the summer sky, calling one another as in a game, showing off, their wings still, as they swoop, clearing the air of mosquitoes and gnats.
"It is time for the century of the rat to end and the century of the swallow to begin," the more determined said. In fact, already beneath the grim and petty rattish dominion, you could sense, among the less obvious people a pondering, the preparation of a swallowlike flight, heading for the transparent air with deft flick of the tail, then tracing with their wings' blade the curve of an opening horizon.
I have come back to Marozia after many years: for some time the sibyl's prophecy is considered to have come true; the old century is dead and buried, the new is at its climax. The city has surely changed, and perhaps for the better. But the wings I have seen moving about are those of suspicious umbrellas under which heavy eyelids are lowered; there are people who believe they are flying, but it is already an achievement if they can get off the ground flapping their batlike overcoats.
It also happens that, if you move along Marozia's compact walls, when you least expect it, you see a crack open and a different city appear. Then, an instant later, it has already vanished. Perhaps everything lies in knowing what words to speak, what actions to perform, and in what order and rhythm; or else someone's gaze, answer, gesture is enough; it is enough for someone to do something for the sheer pleasure of doing it, and for his pleasure to become the pleasure of others: at that moment, all spaces change, all heights, distances; the city is transfigured, becomes crystalline, transparent as a dragonfly. But everything must happen as if by chance, without attaching too much importance to it, without insisting that you are performing a decisive operation, remembering clearly that any moment the old Marozia will return and solder its ceiling of stone, cobwebs, and mold over all heads.
Was the oracle mistaken? Not necessarily. I interpret it in this way: Marozia consists of two cities, the rat's and the swallow's; both change with time, but their relationship does not change; the second is the one about to free itself from the first.
From: the Invisible Cities by Italo Calvino