“I have been used to consider poetry as the food of love.” (45)

This is an allusion to Shakespeare’s Twelfth Night and the phrase “If music be the food of love, play on.” This reference is significant because Twelfth Night is a play about outward appearances– despite the fact that Viola is a woman, she is still seen as a man because Duke only notices that she is disguised as one. In Pride and Prejudice, Austen shows Elizabeth as falling into this same trap: she can only see that Darcy seems to be uncaring on the outside, not that he is truly benevolent on the inside.

Source:

“Twelfth Night: Or, What You Will." Google Books. Web. 13 Mar. 2010. http://books.google.com/books?id=mNweaGcPNlQC&printsec=frontcover&dq=twelfth+night& ource=bl&ots=vriZjlyIgh&sig=i9UYQihvdDkXPeMOJXiIeZ4c1h4&hl=en&ei=urybS OLIMH98AaW9Z2UDg&sa=X&oi=book_result&ct=result&resnum=10&ved=0CCkQ6AEwCQ#v=o epage&q=&f=false.