He does not see that he has failed of both aims, partly
because 'The Revolt' is too abstract, partly because it is too definite.
It is neither one thing nor the other. The feelings apprehended are,
indeed, remote enough; in many descriptions where land, sea, and
mountain shimmer through a gorgeous mist that never was of this earth,
the "material universe" may perhaps be admitted to be grasped as a
whole; and he has embodied his conception of the "moral universe" in a
picture of all the good impulses of the human heart, that should be so
fruitful, poisoned by the pressure of religious and political authority.
It was natural that the method which he chose should be that of the
romantic narrative--we have noticed how he began by trying to write
novels--nor is that method essentially unfitted to represent the
conflict between good and evil, with the whole universe for a stage;
instances of great novels that are epics in this sense will occur to
every one. But realism is required, and Shelley was constitutionally
incapable of realism The personages of the story, Laon and the Hermit,
the Tyrant and Cythna, are pale projections of Shelley himself; of Dr.
Lind, an enlightened old gentleman with whom he made friends at Eton;
of His Majesty's Government; and of Mary Wollstonecraft, his wife's
illustrious mother. They are neither of the world nor out of it, and
consequently, in so far as they are localised and incarnate and their
actions woven into a tale, 'The Revolt of Islam' is a failure. In his
next great poem he was to pursue precisely the same aims, but with
more success, because he had now hit upon a figure of more appropriate
vagueness and sublimity. The scheme of 'Prometheus Unbound' (1819) is
drawn from the immortal creations of Greek tragedy.

He had experimented with Tasso and had thought of Job; but the
rebellious Titan, Prometheus, the benefactor of mankind whom Aeschylus
had represented as chained by Zeus to Caucasus, with a vulture gnawing
his liver, offered a perfect embodiment of Shelley's favourite subject,
"the image," to borrow the words of his wife, "of one warring with the
Evil Principle, oppressed not only by it, but by all--even the good,
who are deluded into considering evil a necessary portion of humanity;
a victim full of fortitude and hope and the Spirit of triumph, emanating
from a reliance in the ultimate omnipotence of Good." In the Greek play,
Zeus is an usurper in heaven who has supplanted an older