I am really lagging behind this week so I will try to keep this response fairly short. I probably should go back and give this section a more thorough reading to do this justice but I need to get reading on completing this week's chapters.

Let's see. I feel that Emma knows Frank is wrong for not doing his duty but as the argument heats up she digs in and gets caught up in the spirit of defending Frank despite her real feelings. Probably, too, she begins to relate to him on some level: around the same age, she shirks her duty in the area of visiting and they both have to deal with 'sick' parents, if you will. In the end I think her position is that Frank is wrong for not coming but that it is excusable and she expects him to be a very likeable and mannerly young man.

Mr. Knightley is arguing from the point of view that a man should always do his duty. He sees Frank's excuses, imo, as hiding behind a sick lady and that he should stand up for himself. He knows that by nature of their rank and position, that the Churchills understand the 'code of behavior' and would not really dispute Frank's need to take a few days to do his duty if spoke up and made it clear that he should. As he apparently doesn't do this, Mr. Knightley sees him as weak. Not only that, since Frank seems to go places that he wishes to go, Mr. Knightley is not disposed to think well of Frank. While it's true he has never met Frank, a great deal of information has been disseminated about him through Mr. Weston for years now and all of his letters are shared around and talked of by all. Mr. Knightley uses information from this as well as the standards of the day as the basis for his judgements. Whether this is right or wrong, well...

Now, his anger at Emma is acceptable to a certain extent to me because he doesn't know that she really believes that Frank is wrong for not coming and he feels frustrated as he knows that she knows what is expected on such occasions. Any anger beyond that, then there is possibly something else going on. I'm not necessarily saying that Mr. Knightley is wrong in his assesment of Frank (I guess time will tell) but his anger does appear to be a bit out of proportion in reference to him. Just my humble opinion.