Commenting on lines 123-29, Hugh Roberts argues that Shelley is expressing "the therapeutic desire for 'absolution,'" but "[t]he possibility of pure 'joyous' transcendence of self in the epiphany of the other is clouded even as he asserts it" (154-55).
Roberts points out that the following lines reiterates Shelley's sense of failure in realizing his vision (155):
We shall become the
same, we shall be one
Spirit within two frames, oh! wherefore two?
One passion in twin-hearts, which grows and grew,
Till like two meteors of expanding flame,
Those spheres instinct with it become the same,
Touch, mingle, are transfigured; ever still
Burning, yet ever inconsumable:
In one another's substance finding food,
Like flames too pure and light and unimbued
To nourish their bright lives with baser prey,
Which point to Heaven and cannot pass away:
One hope within two wills, one will beneath
Two overshadowing minds, one life, one death,
One Heaven, one Hell, one immortality,
And one annihilation. Woe is me!
The winged words on which my soul would pierce
Into the height of Love's rare Universe,
Are chains of lead around its flight of fire--
I pant, I sink, I tremble, I expire! (573-79)
Let me offer an alternative reading of this passage: that Shelley is not saying his words do not allow him to realize his vision; indeed, they are "chains of lead," but these chains of led are what keep his body and mind mortal. What he dreads is the thought of death, that his words cannot keep up with his ethereal vision and, therefore, he is mortally exhausted to the extent that his life is at stake. Transcendence is possible, but only if he is willing to accept "annihilation." I disagree with Roberts when he says that what is annihilated is the "lover's contact with the other"(155). What is at stake here are the identities of subject and object; their amelioration spells the end for both identities. Their essences will disintegrate into the immaterial abyss. Shelley, like Blake, imagines Heaven and Hell as one place.
Roberts, Hugh. Shelley and the Chaos of History: A New Politics of Poetry. University Park: Pennsylvania UP, 1997.