Central to understanding this excellent and witty novel is recognising the very different way in which marriage was though of in Austen's day. Marriage was linked inextricably to social status. Marriage was one way in which women in particular could raise their social status, as they were unable to raise their status through a profession or personal achievement. Thus the novel is based around a series of marriages that have either just happened or are eagerly anticipated. However, the novel seems to suggest, marrying too far above your own social sphere is something that can bring sadness and strife. Mr. Weston's first marriage to Miss Churchill represented a rise in social status for him, but also resulted in a rather unhappy marriage due to the inequality of social position between them. Mr. Weston's second marriage is much happier because both come from a similar social position. This is of course also something seen by Emma's misguided attempts to match Harriet with Mr. Elton, which other characters see as foolish, and which Emma herself recognises was the wrong thing to do. Note how Mr. Elton responds to Emma's suggestion that he liked Harriet:
Miss Smith is a very good sort of girl; and I should be happy to see her respectably settled. I wish her extremely well and, no doubt, there are men who might not object to—Everybody has their level but as for myself, I am not, I think, quite so much at a loss.
Mr. Elton is very clear about the "level" of Harriet and his own level, which do not, in his perspective, connect in any way. Emma's affection and determination blind her to the social realities of Emma's position. Austen seems to suggest therefore that marriage is best when it is between two social equals, as is the case between Emma and Mr. Knightley.