'Oh! you amuse me excessively. I am delighted to find that you can vouchsafe to let your imagination wander—but it will not do—very sorry to check you in your first essay—but indeed it will not do. There is no admiration between them, I do assure you; and the appearances which have caught you, have arisen from some peculiar circumstances—feelings rather of a totally different nature—it is impossible exactly to explain:—there is a good deal of nonsense in it—but the part which is capable of being communicated, which is sense, is, that they are as far from any attachment or admiration for one another, as any two beings in the world can be. That is, I presume it to be so on her side, and I can answer for its being so on his. I will answer for the gentleman's indifference.' She spoke with a confidence which staggered, with a satisfaction which silenced, Mr. Knightley.
Austen, Jane, and George Justice. Emma: An Authoritative Text, Contexts, Criticism. New York: W.W. Norton &, 2012. Print. 242.
I liked this passage because it points out Emma's utter denial of what's actually going on. She doesn't want to believe that there is a 'hidden' relationship and possibly an engagement between Jane Fairfax and Frank Churchill. It is because of her obstinacy and stubborn nature that she refutes the observations made by Mr. Knightley. Mr. Knightley however, has seen evidence of their affections and advances, and yet Emma refuses to listen to reason and see the reality of the situation because she believes herself to be right. Unfortunately we know that her sight can be flawed when considering the motivations and affections of others, as we saw how very mistaken she was about Mr.Elton's feelings in the first Volume. Emma almost seems to be trying to convince herself more than she is Mr. Knightley with this proclamation. She's explaining away the evidence as merely circumstantial, and that their feelings are not of love, but different, and she takes it upon herself to vouch for it on Frank's behalf even if Jane is in love with him.