Nam Sibyllam quidem Cumis ego ipse
oculis meis vidi in ampulle pendere, et cum
illi pueri dicerent: Σίβυλλα τί θέλεις;
respondebat illa: άποθανεΐν θέλω.
-- Petronius, Satyricon
I saw myself, with my own eyes, the Sibyl of Cumae hanging in a bottle; and when the boys asked her: "Sibyl, what do you want?" she responded: "I want to die."
Petronius's story of the Sibyl is the same as that of Tithonus, one of Dawn's lovers. The god Apollo asked his faithful prophetess what gift he could give her, and she asked for eternal life. Unfortunately, she neglected to ask for eternal youth, which Apollo could not afterwards grant her, so that she shriveled and withered over the years into an insect husk of the woman she had once been, living a wretched eternity in a glass bottle.
The poet T.S. Eliot used this passage as the epigram for his great poem "The Waste Land," and indeed his work is filled with prophets living on the edge of chaos: the Sibyl of Cumae shrinking into nothingness; Tiresias, the blind prophet who spent seven years as a woman and now exists as both at once; Madame Sosostris, "the wisest woman in Europe," who foretells fear and death with her Tarot pack; the narrators of "Ash-Wednesday" and "Choruses from the Rock," among others; and Lazarus, come back from the dead only to find that none of the women who come and go (talking of Michelangelo) will hear what he is desperate to tell.
Talking of Michelangelo, that's his work in the header of this site. Observant classicists or art history students will notice that the lady in question is actually the Delphic Sibyl, not her Cumaean sister. I have no real justification for this; I just like her better. She looks a bit like me, I think -- young, wide-eyed, a girl who would be pretty if not for the worry in her face. Sometimes I wonder what she sees; she looks as if the future just walked into the room behind her.
For the record, while I identify with the lady in the veil, I don't go so far as to think I share her powers. I tell a lot of futures, but none of them belong to anyone real. I may see into my own future, at times, but I worry too much to see it truly; I may look like a Sibyl, but my eyes are not so clear.
I am no prophet -- and here's no great matter;
I have seen the moment of my greatness flicker,
And I have seen the eternal Footman hold my coat, and
And, in short, I was afraid.
-- T.S. Eliot, "The Love Song of J. Alfred Prufrock"