Prometheus: Submission, thou dost know I cannot try:
For what submission but that fatal word,
The death-seal of mankind's captivity,
Like the Sicilian's hair-suspended sword,
Which trembles o'er his crown, would he accept,
Or could I yield? Which yet I will not yield.
Let others flatter Crime, where it sits throned
In brief Omnipotence: secure are they:
For Justice, when triumphant, will weep down
Pity, not punishment, on her own wrongs,
Too much avenged by those who err.

In the first act of Shelley's play, Prometheus, who has stolen fire from the gods and is being punished by the god Jupiter, says he ain't gonna to apologize to the big bully Jupiter.

It's interesting that Shelley wrote the play Prometheus Unbound not to be performed, but to be read. That's because its scope is so ambitious. The language is really grand and the characters are larger than life (Asia and Ocean are characters in the play, as an example).

So here we see Shelley rebelling against the conventions of theater. Who says plays have to performed? The imagination can be our stage—we can visualize the play in our minds, rather than watch it in front of us, can't we? It's a play about a rebellious character, and the form and style of the play go against theatrical convention.