By an epiphany he meant a sudden spiritual manifestation, whether in the vulgarity of speech or of gesture or memorable phrase of the mind itself. He believed it was for the man of letters to record these epiphanies with extreme care (saving them for later use, that is), seeing that they themselves are the most delicate and evanescent of moments.

James Joyce: The Poems in Verse and Prose (ed. Trafalgar Square, 1996)