Allusion: a figure of speech, reference/representation of/to a well-known person, place, event, literary work, or work of art. M.H. Abrams defined allusion as "a brief reference, explicit or indirect, to a person, place or event, or to another literary work or passage"
S'io credesse che mia risposta fosse
A persona che mai tornasse al mondo,
Questa fiamma staria senza piu scosse.
Ma perciocche giammai di questo fondo
Non torno vivo alcun, s'i'odo il vero,
Senza tema d'infamia ti rispondo. (1)
Functioon: This section is added to The Love of Alfred Prufrock, it comes from Dante's Divine comedy, which is the story of a mans journey into hell, purgatory, and then heaven. T.S. Elliot included this exerpt perhaps to clue us into what torment the speaker is in. EH is faced with a terrible fate. roughly translated it says, If I thought that that I was replying to someone who would ever return to the world, this flame would cease to flicker. But since no one ever returns from these depths alive, if what I've heard is true, I will answer you without fear of infamy." It gives a gloomy feel to the poem, and anticipation for what will come.