Perhaps it comes down to the assymetrical `rights' of men and women. A man had the right to choose any woman, but a woman had only the right of acceptance or refusal of a man who had already chosen her. However, to even things up a little, she had the right of refusal right up to the wedding ceremony. Jane Fairfax is another woman who breaks an engagement, and nobody seems to think the orse of her for doing it.

Edward has gone one step further than Henry and Wentworth: he's actually engaged, and he would have been breaking a promise. But Henry and Wentworth have only raised expectations, so they have a little more freedom: Henry actually wants to marry Catherine, so he can use the raised expectations as a further reason to do what he wants: Wentworth, on the other hand, does a runner so as to get out of it. It would have been caddish for them to have failed to marry the woman whose expectations they have raised, and they aren't cads. All the same, I think Wentworth would have been overscrupulous to marry Louisa if he really wanted to marry another woman who also wanted to marry him.