The Nurse, after a few brief moments on stage, is already well-defined as a character. She is loyal to the house and to Medea, but she fears Medea and her violent heart. The slaves provide an outsider's eye on the action, and they are canny enough to predict events. The Nurse's fears foreshadow the terrible fate of Medea's children. And yet the slaves are completely powerless to alter the course of events.
Passion is an important theme of the play.
The Nurse reminds us that Medea is here because she followed Jason back to Greece out of love. To win back his rightful place in Iolcus, she turned the daughter of Pelias into murderers. As long as Jason returned her love, Medea's power and passion were enlisted for his aid. Greatness and pride are two more themes, closely connected. The Nurse speaks of the dangers of great people's passions.