"Don't be defeatist dear, it's terribly middle class."
"I'm a woman, Mary. I can be as contrary as I choose."
"It always happens when you give these little people power, it goes to their heads like strong drink."
"We are allies, which can be a good deal more effective [than friends]."
Lady Mary Crawley: "Sybil is entitled to her opinions."
Lady Grantham: "No. She isn't until she is married, then her husband will tell her what her opinions are."
Sir Richard Carlisle: "I'm leaving the morning Lady Grantham, I doubt we'll meet again."
Lady Grantham: "Do you promise?"
“I was right about my maid. She’s leaving – to get married! How could she be so selfish?”
“We’ll have to take her abroad, in these moments you can usually find an Italian who’s not too picky.” (about finding a suitable match for her granddaughter)
“I couldn’t have electricity in the house. I couldn’t sleep a wink. All those vapours seeping about.”
“I don’t dislike him, I just don’t like him. Which is quite different.”
“One can’t go to pieces at the death of every foreigner. We’d all be in a constant state of collapse whenever we opened a newspaper.”
“I do hope I’m interrupting something.”
“Sir Richard, life is a game, where the player must appear ridiculous.”
"Nothing succeeds like excess."
Lady Grantham: “That is a scruple no successful wife can afford.”
Lady Grantham: “Why would you want to go to a real school? You’re not a doctor’s daughter.”
Sybil: “Nobody learns anything from a governess, apart from French and how to curtsy.”
Lady Grantham: “What else do you need? Are you thinking of a career in banking?”
Doctor: “Mrs. Crawley tells me she has recommended nitrate of silver and tincture of steel.”
Lady Grantham: “Why, is she making a suit of armor?”
quotes found here and here