Conlfict between the old and the new, between savagery and civilization, between the primal and the rational
This theme is expressed in the progression of old to new gods. Zeus overthrew the older generations of gods, and among these ancient deities were the Furies. The Furies have been made outcasts. The deities are the embodiments of opposing forces: Apollo is a symbol for the male, the rational, the young, and the civilized. The Furies represent the female, the violent, the old, and the primal. Aeschylus captures a mythical moment in history, one in which the world was torn between a savage and archaic past and the bold new order of Greek civilization, the young Olympian gods, and rationality. The difficulty of the struggle between these two worlds is dramatized by the cycle of violence in the House of Atreus and the clash between Apollo and the Furies. The Oresteia is about the growing pains of a nascent civilization.
Reconciliation of opposites
The goal of the above struggles is not the annihilation of the old ways. The old must be integrated with the new. The central theme of this play is the struggle/conflict between opposites, and the reconciliation of those opposites. Athene herself is a symbol for that kind of reconciliation. She is female, but she is also a warrior: Aeschylus has her enter dressed in full body armor. She is as rational as her half-brother Apollo, but she is also compassionate and does not react with disgust at the sight of the Furies. She is woman, but she is born of her father: according to myth, she sprang from her father's skull. She is the goddess of wisdom and crafts as well as warfare, making both the creative and the destructive within her jurisdiction. She reconciles the best attributes the Greeks traditionally ascribed to the masculine and the feminine. The action of the play is to integrate the ancient and the primal with the new and the civilized; this integrations means bringing the Furies into the new world order.
Fear and justice
Another important pair of opposites, which deserves its own entry. According to the vision of the Oresteia, fear is a sister to justice. Both are necessary for the preservation of order. The rationality of the Olympians, with their trials, orderly proceedings, and plans, must be combined with the terrifying brutality of the Furies. As the trilogy depicts things, the Furies' archaic version of justice, with its emphasis on fear and punishment, must not be totally abandoned.
Cleansing/purification
Finally, in this play the Curse on the House of Atreus will be washed away. The Furies constantly say that Orestes' hands are bloodstained because of his matricide, and until the trial, he will not be free of them. In previous plays, the Curse was spoken of symbolically in terms of blood and poison; the House of Atreus was sick and corrupt from the sins of its own past. Finally, it will be healed.
History
Although this theme has the most presence in the first part of the trilogy, the burden of the past is part of the whole trilogy. Two themes come together in the Curse: the theme of history and the theme of violence's self-perpetuating nature. The whole bloody history of the House of Atreus continues to affect events in the present. Orestes was able to go through with the murder because of the orders of Apollo and because the force of history propelled him forward. The legacy of the House of Atreus and the Trojan War, as well as the commands of Apollo, drove Orestes toward his fate. This theme is closely connected to the divine plan and Aeschylus' methods of explanation.
Teleology/the Divine Plan/Fate
Part of Aeschylus' project is to fit the story of the House of Atreus into a grand design, explaining events in terms of the progress of civilization. The murders in the house all are made to fit into an explanatory model that makes us understand the future and the past. Orestes was aware of the Curse on his house, and he hoped that in killing his mother he would put an end to the cycle of violence. By The Eumenides, we know that getting rid of the Curse will not be so simple. But by the end of the end of the whole trilogy, Orestes will have been key not only to ending the Curse, but also in laying the foundation for a new step in the progress of humanity. The Olympian gods have a great part in this progress, and their plans make possible a more civilized future. We are made to see the events of the trilogy as part of a grand design, a design that has ramifications not only for the characters of the play but for all of mankind.
The self-perpetuating nature of violence
Violence begets violence; the murders of Thyestes children continue to plague the House of Atreus two generations later. Although each new murder has its justifications, every new killing inevitably leads to other new killings. Thyestes' Curse is part supernatural, and partly a result of the nature of violence itself. Finally, the gods must intervene to put a stop to the murders.
Conflict between different moral systems
The Greeks were acutely aware of the tendency of different moral systems to come into conflict. Many tragedies feature two opposing characters who defend different moral systems, with each character being right in his own way. In The Libation Bearers, when Orestes doubted if he could kill his own mother, Pylades told him that he should count all men hateful to him rather than the gods. Orestes was ordered by the god Apollo to kill Clytaemestra. He had the right to vengeance; she killed his father, and Orestes has responsibility to his dynasty. But Clytaemestra was also his mother. Orestes made a choice, and though his actions were justified, he cannot commit matricide without consequences. At the trial, the Furies and Apollo argue from two different standpoints, both of which have their own logic and moral code.
