allusion: a reference in a literary work to a person, place, or thing in history or another work of literature. Allusions are often indirect or brief references to well-known characters or events. Specific examples of allusions can be found throughout Dante’s Inferno. In a passage, Dante alludes to the Greek mythological figures, Phaethon and Icarus, to express his fear as he descends from the air into the eighth circle of hell. He states:

I doubt if Phaethon feared more - that time
he dropped the sun-reins of his father's chariot
and burned the streak of sky we see today -
or if poor Icarus did - feeling his sides
unfeathering as the wax began to melt,
his father shouting: "Wrong, your course is wrong"

Allusions are often used to summarize broad, complex ideas or emotions in one quick, powerful image. For example, to communicate the idea of self-sacrifice one may refer to Jesus, as part of Jesus' story portrays him dying on the cross in order to save mankind. In addition, to express righteousness, one might allude to Noah who "had no faults and was the only good man of his time". Furthermore, the idea of fatherhood or patriarchial love can be well understood by alluding to Abraham, who was the ancestor of many nations. Finally, Cain is an excellent example to convey banishment, rejection, or evil, for he was cast out of his homeland by God. Thus, allusions serve an important function in writing in that they allow the reader to understand a difficult concept by relating to an already familiar story.