How we cite our quotes: Citations follow this format: (Chapter.Paragraph)
Quote #7
"This will not do," said Catherine; "I cannot submit to this. I must run after Miss Tilney directly and set her right."
Isabella, however, caught hold of one hand; Thorpe of the other; and remonstrances poured in from all three [....] When every thing was settled, when Miss Tilney herself said that Tuesday would suit her as well, it was quite ridiculous, quite absurd, to make any further objection.
"I do not care. Mr Thorpe had not business to invent any such message." (13.17-19)
What constitutes a lie is debated here. The Thorpes and James think that it's fine to tell a convenient white-lie, while Catherine objects to lying of any kind. She especially objects to John interfering and lying on her behalf.
Quote #8
To Catherine's simple feelings, this odd sort of reserve seemed neither kindly meant, nor consistently supported; and its unkindness she would hardly have forborn pointing out, had its inconsistency been less their friend; - but Anne and Maria soon set her heart at ease by the sagacity of their "I know what;" and the evening was spent in a sot of war of wit, a display of family ingenuity; on one side in the mystery of an affected secret, on the other of undefined discovery, all equally acute. (15.26)
The diction (or way of speaking) here really hammers home to true nature of the Thorpe family, who are really good at using wit and deceit. The Thorpes are inconsistent, unkind, and ingenuous, or good at inventing things.
Quote #9
What could be meant by such unsteady conduct, what her friend could be at, was beyond her comprehension. Isabella could not be aware of the pain she was inflicting, but it was a degree of willful thoughtlessness which Catherine could not but resent. (19.1)
This passage suggests that deceit and careless behavior can be a matter of inattention. Though Catherine's internal use of the world "willful" suggests that she is somewhat aware of the degree to which Isabella is aware of her callous, or mean, behavior.