And even in our sleep pain, which cannot forget, falls drop by drop upon the heart, until, in our own despair, against our will, comes wisdom through the awful grace of God. — Aeschylus, from the chorus in Agamemnon; The Oresteia: Agamemnon; The Libation Bearers; The Eumenides, transl. Robert Fagles (Penguin Classics, 1984)