One of the more obvious themes that Austen deals with in Pride and Prejudice is pride among society. Austen explores pride among both the aristocracy and among the middle class society, such as Elizabeth's class. Darcy and Elizabeth discover that, unbeknown to themselves, they both have excessive pride. We see Elizabeth's self-realization when she declares,
I, who have prided myself on my discernment!....I have courted prepossession and ignorance, and driven reason away. (Ch. 13, Vol. 2)
Likewise, Darcy's self-realization is seen in the lines, "I was given good principles, but left to follow them in pride and conceit" (Ch. 16, Vol. 3).
Another more obvious theme is prejudice. Elizabeth discovers that due to his class and his reserved nature, Elizabeth had accused Darcy of being a horrible, arrogant, and prideful person.
Another less obvious theme contrasts the idea of romantic points of view with more practical view points. Both Jane and Elizabeth want to marry for love. Elizabeth is especially appalled when Charlotte Lucas accepts Mr. Collins's proposal for the sake of being well provided for, yet we soon learn that Charlotte has made the right decision.
These themes are especially portrayed through Austen's use of point of view. Since Austen uses third-person omniscient point of view with a focus on Elizabeth, we get to hear the narrator philosophize about the themes, but we also get to witness Elizabeth's revelations.
Mood is a second feature that helps shape these themes. Austen's mood is spiced up with a great deal of irony. The irony serves to make thematic points both amusing and emotionally intense.