Pride and Prejudice talks about friendship a lot, especially how friends should or could influence each other.
Mr. Darcy influenced Bingley to leave Jane, in the name of friendship, because he felt she didn't truly love Bingley. Should Bingley have listened to his friend's advice? Was Darcy too presumptuous to interfere? Could someone amiable be friend with someone arrogant and unpleasant?
Charlotte ignored Elizabeth's words and found herself married the silly Mr. Collins with contentment. Should people allow different in temperament when we give out advice to friends.