Theme Analysis

Pride and Prejudice was first titled First Impressions, and these titles embody the themes of the novel. The narrative describes how the prejudices and first impressions (especially those dealing with pride) of the main characters change throughout the novel, focusing on those of Elizabeth Bennet. 
Elizabeth's judgments about other characters' dispositions are accurate about half of the time.  While she is correct about Mr. Collins and how absurdly self-serving he is and about Lady Catherine de Bourgh and how proud and snobbish she is, her first impressions of Wickham and Darcy steer her incorrectly.  Wickham is first thought to be a gentleman by all.  His good looks and his easy manner fool almost everyone, and Elizabeth believes without question all that he tells her of Darcy. Elizabeth's first impressions of him are contradicted when she realizes that he has lied about Darcy.
Elizabeth and many of the other characters see Darcy as proud, and it can be seen from this quote just how quickly this judgment of him is formed.
"The gentlemen pronounced him to be a fine figure of a man, the ladies declared he was much handsomer than Mr. Bingley, and he was looked at with great admiration for about half the evening, till his manners gave a disgust which tuned the tide of his popularity; for he as discovered to be proud, to be above his company, and above being pleased; and not all his large estate in Derbyshire could then save him from having a most forbidding, disagreeable countenance, and being unworthy to be compared with his friend" (58).
It is not only what she believes to be pride in Darcy's character that makes her judge him harshly, but also her prejudice against him because of the lies Wickham has told her. Darcy sees this fault of prejudice in Elizabeth, stating that her defect is "willfully to misunderstand everybody." In the end Elizabeth realizes her folly in trusting her first impressions and prejudices about the men, and states, "how despicably have I acted. I, who have prided myself on my discernment! - I, who have valued myself on my abilities."
The above are only a few of the major examples of first impressions, prejudice and pride in the novel, as these themes show up throughout the story. Characters besides Darcy are also accused of having too much pride, such as Bingley's sisters, Miss Darcy, Lady Catherine and others. There are also discussions about pride between Elizabeth and Darcy, and Mary discusses pride vs. vanity.  Characters are also described as being proud on certain occasions.  For example, Mrs. Bennet is described as visiting her married daughters with pride, and Elizabeth is said to be proud of Darcy because of what he had done for Lydia.  First impressions can be discussed of many of the other characters than those discussed here, and prejudice is illustrated not only in Elizabeth's behavior, but in Darcy's and Lady Catherine's reactions to the status of Elizabeth's family as well.