Chapter 14:

A woman, especially, if she have the misfortune of knowing any thing, should conceal it as well as she can.

...in justice to men, that though, to the oarger and more trifling part of the sex, imbecility in females is a great enhancement of their personal charms, there is a portion of them too reasonable, and too well-informaed themselves, to desire anything more in woman than ignorance.

...he shortly found himself arrived at politics; and from politics it was an easy step to silence.

I also like this,from Ch. 12:
(Catherine is intreating Mrs. Allen to corroborate her story): "Did not they tell me that Mr TIlney and his sister were gone out in a phaeton together? ...But I had ten thousand times rather have been with you. Now, had not I, Mrs. Allen?"