How we cite our quotes: (Act.Scene.Line)
Quote #1
Diamonds are of most value,
They say, that have passed through most jewellers' hands (1.1.92-93)
In the face of her brothers' insistence that she not remarry, the Duchess shoots back that women are like diamonds that accrue value by being hitched. So there.
Quote #2
Ferdinand: Let not youth, high promotion, eloquence—
Cardinal: No, nor any thing without the addition, honour,
Sway your high blood.
Ferdinand: Marry? They are most luxurious
Will wed twice. (1.1.288-291)
First, you have the Cardinal, telling the Duchess that she can't let her "blood" be swayed. This has a double meaning: in one hand he's warning her about the sway-ability of her "blood," using the word to refer to her sexual desires and passions; on the other hand, he's also referring to her blood as her aristocratic lineage, which can be jolted off-course by the Duchess's choosing to remarry and mix her blood with somebody else's. Second, you have Ferdinand, talking about the "luxury" of widows who remarry, playing off the idea of widows as being lecherous and uncontrollable.
Quote #3
Shall this move me? If all my royal kindred
Lay in my way unto this marriage
I'd make the my love foot-steps, and even now,
Even in this hate, as men in some great battles,
By apprehending danger have achieved
Almost impossible actions—I have heard soldiers say so—
So I, through frights and threat'nings will assay
This dangerous venture. Let old wives report
I winked and chose a husband. (1.1.333-45)
The Duchess has clearly got impressive reserves of chutzpah. She's just calmly told her brothers that, yeah, no worries, she won't remarry without their say-so, only to turn around and baldly announce that she'd walk over the bodies of them and the rest of her lineage to get to the altar with Antonio. She's not merely transgressive here; this is downright audacious. The other neat thing to notice is her reliance on masculine, heroic language here; the Duchess is talking about soldiers and great battles to authorize her decision to remarry. She's a prince, damn it, she's gotta do what she's gotta do.