I know of no man more likely than Mr. Knightley to do the sort of thing–to do any thing really good-natured, useful, considerate, or benevolent. He is not a gallant man, but he is a very humane one.

Mr. Knightley is a unique romantic hero in that he is entirely realistic – he’s not a prince, or a hero, or any other kind of grand, dashing man who might be considered an “ideal” in women’s romantic fantasies. And yet, his realistic nature makes him all the more attractive to Emma. He is not a fantasy, he is a real person who contains everything that a good partner and good man should. When the flattery and chivalry of Mr. Elton are stripped away, he is exposed to be a smarmy, dishonest striver with a cruel streak. When the flirtatiousness and sociableness of Frank Churchill are stripped away, he is exposed to be childish, careless, and lacking in a sense of responsibility. There is nothing lacking or deceptive in Mr. Knightly. He is, as Emma says, consistently useful, compassionate, and good throughout the entire novel. Although Emma doesn’t realize it yet, she is describing exactly what it is about Mr. Knightley that has caused her to fall in love with him.

Mr. Knightley and Jane Fairfax!...Mr. Knightley must not marry!--You would not have little Henry cut out from Donwell?--Oh! No, no, Henry must have Donwell. I cannot consent to Mr. Knightley’s marrying; and I am sure it is not at all likely.

When Mrs. Weston suggests that Mr. Knightley might be in love with Jane Fairfax, Emma immediately comes up with multiple reasons why that must not be the case, and why it would be unfortunate for Mr. Knightley to marry. Her most concrete reason is that, should Mr. Knightley marry, his nephew Henry would no longer be the primary inheritor of the Donwell estate. Of course, this is not the real reason why Emma doesn’t want Mr. Knightley to marry – she doesn't realize it yet, but her adamant insistence that Mr. Knightley will not marry Jane Fairfax is born from her own feelings for him. She’s horrified by the idea of him marrying another woman. Later in the novel, when Emma and Mr. Knightley are engaged, she wryly remarks that when considering the particulars of her own marriage to Knightley, she never once felt concerned that Henry would no longer inherit Donwell.

The only source whence any thing like consolation or composure could be drawn, was in the resolution of her own better conduct, and the hope that, however inferior in spirit and gaiety might be the following and every future winter of her life to the past, it would yet find her more rational, more acquainted with herself, and leave her less to regret when it were gone.

These lines come late in the novel, after Emma has made several blunders that have humbled her deeply. She has insulted Miss Bates and has realized how very poor her conduct has been toward Miss Bates for some time. Even worse, her matchmaking manipulations have caused Harriet to set her sights on Mr. Knightley, forcing Emma to admit her feelings for Mr. Knightley and how miserable she would be if he married another. Afraid that Knightley might return Harriet’s affections and that she may lose him forever, Emma reflects on her bad decisions, her poor treatment of others, and her future should she face the consequences she dreads. Emma shows maturity and incredible growth from the beginning of the novel by vowing that, going forward, she will choose wisdom and rationality over gaiety and fun. Even if she were to lose Mr. Knightley to Harriet, Emma takes consolation in the fact that she has learned from her mistakes and will not make the same ones in the future.