How we cite our quotes:
You have chosen a very pretty and a very affectionate creature. It will be your duty, and it will be your pleasure too—of course I know that; I am not delivering a lecture—to estimate her (as you chose her) by the qualities she has, and not by the qualities she may not have. (44.63)
Miss Betsey gives David some sage advice here about how to handle Dora. Now that David realizes that Dora can't be serious, he starts to feel disappointed. Miss Betsey basically instructs him that, if he can't be with the one he loves (his ideal partner, a fantasy who he has yet to identify as Agnes), he should love the one he's with. What lessons is Miss Betsey drawing on from her own life to impart this moral? And is disappointment something that you can just choose not to feel?