The Chorus, in the "Agememnon," the first of the three plays, responds to Agamemnon's death and trying to grasp the limits of the older form of justice by revenge:
Here is anger for anger. Between them
who shall judge lightly?
The spoiler is robbed; he killed, he has paid.
The truth stands ever beside God's throne
eternal: he who has wrought shall pay; that is law.
Then who shall tear the curse from their blood?
The seed is stiffened to ruin. (Aeschylus, Agamemnon
The chorus recognizes the legitimacy of the older justice of blood for blood, anger for anger, sword for sword. But asks a question: "Then who shall tear the curse from their blood?" When, indeed, does the cycle of revenge and counter-vengence ever stop in an ever devolving spiral of violence?