The theme is man's absurdities — not the high-minded and exceptional absurdities of tragedy or the grim ones of Swiftean satire, but those common, frequent, and more laughable ones of society, its code of manners, and its fabricated engagement of man's time, thought, and energy.
Beneath Austen's satiric comedy is a moralistic realism. By picturing the real incongruities of social matters, she implies what may be right: the ideal balance between head and heart, between common sense and goodness, between rationality and imagination or emotion. Hers is not a naturalistic world inimical to or destructive of the individual. Rather, it is a fairly stable social world that operates comfortably as long as there is no major aberration from it. It can, in fact (if we judge from the outcome of the story), operate effectively in spite of an aberration, secure that the deviation can be rectified and absorbed so that the deviant (Emma) finds and accepts her proper place.
It is against this background that Emma pursues her willful and subsequently crossed-purpose way. In the end her change is not into something new and different from her time and place, but into something that is the standard of her environment. Her change is not the kind associated with a liberal idea of progress, but the kind found in the conservative idea of progress: she develops into, not out of, a social tradition. Thus a major thematic irony of the book is that at the end Austen lets the reader see that, in spite of the surface doubts and disturbance, there was never any real danger that the environmental fabric would be changed because of, or for, Emma. This certainty is driven home by the comfortable (and, literarily, conventional) pairing off of the marriageable couples.
Nevertheless, the triumph of this social world does not mean that it is necessarily the best of its kind. Thematic satire at the expense of the manners and people of this world is given throughout the book. A crowning irony comes at the very end when Emma and George can be comfortably paired off in marriage only because the robbing of poultry houses makes Mr. Woodhouse want George around for protection. Such a relationship between cause and effect — between the ludicrous and the desirable — underscores the inclusive satirical theme of incongruity. By moralistic implication a world of balanced congruities is yet to be attained.