The degree to which Mr. Bennet's apathy and ineffectualness harm his family is most clear in his response to Lydia's elopement. That he recognizes the significance of Lydia's action is obvious from his initial anger and trip to London. From what Austen has shown us of him, we know that Mr. Bennet must be extremely affected by something to be persuaded to leave his library, much less his home, for an extended period of time. However, despite his burst of activity, he is unable to resolve the situation and, turning the problem over to his brother-in-law, Mr. Bennet returns home to settle back into his former attitude of indifference. His indifference is such that, even when Mr. Gardiner writes to communicate the good news of Lydia and Wickham being discovered, Mr. Bennet goes for a walk rather than immediately sharing the news with the family. Even after Jane and Elizabeth wring the news out of him, it takes all of their coaxing and persuasion to get him to respond to Mr. Gardiner. Instead of being happy that Lydia is safe and the family's reputation is saved, Mr. Bennet frets over the financial obligation he now feels toward Mr. Gardiner.
Lydia's marriage to Wickham provides Austen with another opportunity to explore the marriage theme that runs through the novel. Remember that the last wedding to occur was Charlotte's marriage to Mr. Collins. Elizabeth disapproved of such a marriage of convenience, but her visit to Hunsford showed her that although Charlotte lacks love and respect for her husband, she is relatively happy with her home and situation. The implication there, then, is that while a marriage of convenience may not be ideal, it can be made to work.
