] So Captain Tilney is NOT one to go around flattering women and falling in love.

ah, ah, ah... hold on there, missy! ;-) I agree that Capt. Tilney is not one to fall in love, BUT he certainly is one to go around flattering women - we see him do it, and with Catherine as a witness.

] This is my theory: he starts out with lively flirting at the ball. When they get home, I am sure that he and Henry discussed the girls. Frederick would have seen that Catherine was in love with Henry and questioned him about her. Finding out that her brother was engaged to Isabella, perhaps Frederick chose to see if he could separate them?

The flaw in this theory, is that Frederick knew Isabella and James were engaged right from the first moment. When he flirted and danced with her at the Assembly, he already knew she was spoken for.

I certainly do not put all the blame for Frederick and Isabella's flirtation on his shoulders. IT deserves most of it, and if some other, richer man than James had come along and experssed an interest, she would have done the same.

But I do blame him for knowingly pursuing an engaged woman and then carrying on in the fashion he did, regardless of the pain he knew he was causing others, especially James. Isabella was wrong is seeking such attentions, but he was equally wrong in giving them. Henry himself admits this not unusual behaviour for him and that he did it just for mischief.