What is the theme in Seven against Thebes by Aeschylus?

Choice and fate make up the theme. Eteocles recognizes that the gods are in control of his destiny. When the Chorus begs Eteocles not to meet his brother, Polyneices, in battle, Eteocles says that fate has already determined his future: "Why kneel to Fate when sentenced to death already? " This surrendering to fate allows Eteocles a way to escape responsibility for his actions.