(Apollo): "Do not weary […] by brooding on this ordeal, but go to Pallas' city and seat yourself there, clasping her ancient statue; and there we shall have judges for this matter, and words to win them over, and find means to release you once and for all from these miseries." (78-83)
Isn't the whole point of trial by jury supposed to be that it's impartial? Doesn't an impartial judgment usually mean that you don't know in advance what the judgment is going to be (because the judge and jury have to listen to each case patiently)? If so, then what do we make of the fact that Apollo is convinced that he will find "words" to "win […] over" the judges to Orestes's side and "find means to release [him] once and for all from these miseries"? Is Apollo just trying to cheer Orestes up, or is he really so cynical about the whole judicial process?
(Clytemnestra's Ghost): "Hey! Stay asleep, then, do! And what's the use of your sleeping? Here am I dishonoured like this among the other dead because of you, and with the slain ceaselessly reproaching me for those I killed; and I wander in shame. I tell you solemnly that they accuse me very much; and that although I have suffered so terribly from my closest kin, not one divine power is angry on my account, although I was slaughtered by the hands of a matricide." (94-102)
By bringing the Ghost of Clytemnestra onstage, Aeschylus shows us that Orestes's actions in killing his mother were not merely abstract—there was a real victim involved, who gets to express her feelings in these lines. This reminds us that there is right on both sides of an argument.
(Chorus of Furies):
"Such things as these are done by younger gods
with power wholly beyond justice
at the throne dripping with murder
all round its foot, all round its head.
I can see before me
the earth's navel, which has taken
bloodshed on itself, a ghastly defilement to have." (162-168)
These lines remind us that the Furies in the play always portray themselves as speaking in the name of justice. Of course, if you actually look at what they mean by justice, it's pretty terrifying. Like, we don't know exactly what "justice / at the throne dripping with murder / all round its foot, all round its head" means, but it sounds pretty freaky. The problem for Apollo, Athena, and the other characters in the play will be convincing the Furies that their interpretation of justice isn't the only one.
(Apollo): "It is quite improper that you approach this temple—go rather where justice is decapitation and gouged-out eyes, and slaughtered throats; where boys' downy virility is foully destroyed by castration; where extremities are amputated and stonings done; and where men impaled up into their spine moan long and piteously. Do you hear? This is the kind of festivity for which your fondness makes you abominable to the gods." (185-191)
Here, once again, we see the conflict between different ideas of justice. By listing all these horrible tortures and punishments, Apollo implies that the Furies' idea of justice isn't justice at all.
(Apollo): "A man and wife's marriage-bed once under destiny is greater than any oath, with justice as its guardian. If therefore you are lax in exacting payment from them when they kill each other, and in watching over them with your rancor, I say you are driving Orestes into exile unjustly. I know that you lay the one thing very much to heart, but evidently you pursue the other more gently. Pallas however will watch over the pleas in this case."
(Chorus of Furies): "I will never leave this man alone!" (217-225)
So what's Apollo saying here? Basically, it looks like he's accusing the Furies of being inconsistent. How can they be chasing down Orestes, planning to kill him, when they didn't do anything to punish Clytemnestra for killing her husband Agamemnon? That looks pretty unfair, doesn't it? And what's unfair can't be just, can it? The Furies' lame comeback ("I will never leave this man alone!") certainly looks like they're just trying to avoid getting beaten in the argument.
(Chorus of Furies):
"And when I have withered you I will lead you off below, alive,
to pay the penalty for the matricide and its horror.
You shall see too every other mortal man who has sinned
in not reverencing a god or a stranger
or his own parents,
each one with his just deserts.
Hades is mortal men's great auditor
beneath the earth;
with the written tablets of his mind he watches over everything." (267-275)
Here, the Furies express a belief in divine justice. The god of death (Hades) presides over a kingdom of dead souls who have all gotten their own "just desserts." This still places the Furies in opposition to the view of justice put forward at the end of the play, however, which is (partly) in human hands.
(Chorus of Furies): "We think we are straight in our justice:
no anger from us comes against those
who hold out pure hands,
and each walks through his life without harm;
but to any who sins like this man here
and conceals bloody hands,
we appear as true witnesses in support of the dead,
exacting payment for bloodshed from authority." (312-320)
Once again, the Furies claim to be just because they are equal in how they dispense justice. In this case, their claim boils down to the famous boast of the Royal Canadian Mounted Police that "we always get our man." But doesn't this just open them up to the same complaint that Apollo made: that the Furies are actually inconsistent because they didn't hunt down and punish Clytemnestra for killing Agamemnon?
(Athena): "Whoever are you? I speak to all in common, both this stranger seated at my statue [a line missing], and you who are like no kind of begotten things, neither belonging to goddesses seen by gods nor yet resembling human forms. But to speak ill of people at hand who give no cause for blame, is to assume a right far distinct from justice." (408-414)
Here, Athena basically says that she isn't going to judge anybody before she knows all the facts. How does this contrast with Apollo's words to Orestes earlier in the play?
(Chorus of Furies): "Catastrophe now is coming
from new ordinances, if a justice
which is harm to justice shall prevail
for this man here, the matricide.
This day's work will at once accustom
all men to licence;
and much veritable suffering, which their own children
will inflict, lies waiting for parents
in time hereafter." (490-498)
These are the Furies' words right before the trial gets started. As you can see, this isn't just an ordinary question of guilt or innocence, but actually pits two very different conceptions of justice against one another—that of the Furies and that of Apollo, Orestes and Athena. Is there any advantage to the view of justice that the Furies represent, or are we kind of forced to sympathize with the other side?
(Apollo) (to the jurors): "I shall say to you, who are here by Athena's great ordinance, that [the blood of Clytemnestra] was shed justly; and as prophet I shall not lie. I never yet said at my prophetic throne, not about man, not about woman, not about city, except what Zeus the Olympian Father might command. I tell you plainly: understand how strong this just plea is, and heed the Father's will; an oath is in no way stronger than Zeus." (614-621)
Here Apollo makes a different type of argument for the justice of Orestes than the ones we have seen so far. Here, he says what Orestes did was just (a) because Apollo told him to do it, (b) because Apollo never lies, but only say what Zeus "might command," and (c) because whatever Zeus "might command" would be just. (The last point, (c), is just implied by Apollo's words; he doesn't come out and say it directly.)
Now, this last, implied point, actually begs a question. Is what Zeus commands just because Zeus would never command anything other than what is just already… or is what he commands just because he commands it? This brain-teasing question has been part of the history of Western thought for a long time. If reading Aeschylus's play makes you interested in it, you should read Plato's dialogue called the Euthyphro, which treats the problem in some detail. But don't be surprised if even Plato doesn't offer a final answer to this problem…