In Romantic Ideology, Jerome McGann uses lines 573-87 from Epipsychidion to illustrate what he identifies as the "powerful sensationalism" the second-generation romantic poets:
When we turn to the later Romantics the differences appear in Character rather than in kind, though they are none the less clear for that. All the positions taken up by the early Romantics assume more extreme forms in the later Romantics--an aesthetic of arresting surface effects, a physique of poetry. Shelley's overwhelming verse effects--one recalls especially Act II scene 5 of Prometheus Unbound, or the concluding stanzas of Adonais, or various passages in "Epipsychidion"--illustrate his version of this new poetic mode very well. (115)
Here is the passage from Epipsychidion--lines 573-87:
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!
McGann continues:
One could cite analogous examples out of Byron's kaleidoscope or Keats's voluptuousness, but two of their brief prose remarks are perhaps even more telling:
the great object of life is Sensation--to feel that we exist--even though in pain. (Letter to Annabelle Milbanke, 6 Sept. 1813)
O for a Life of Sensations rather than of Thoughts! (Letter to Bailey, 22 Nov. 1817)
From the earliest commentators, like Hazlitt and Hallam, to the most recent, readers have always remarked on this difference between Byron, Shelley, and Keats on the one hand, and Wordsworth and Coleridge on the other, and many have used the difference to set (or insinuate) comparative valuations, usually to the detriment of the later Romantics. Such differences have to do with poetic style and ideology, however, not with the relative success in the poetic craft. Indeed, I do not see how the later Romantics could have written poetry at all without finding an appropriate stylistic means for revealing the special human truths of their worlds--a poetry capable of reciprocating the forms of life and behavior peculiar to the period which extends from the opening of the Penninsular War to Byron's death just prior tot he close of the Greek struggle for independence.
These special circumstances affected the earlier Romantics as well. Blake fell silent, Wordsworth fell asleep, and Coleridge fell into his late Christian contemputus. The second generation Romantics, however, fashioned from these evil times a new set of poetic opportunities. Three sorts of poetry may be particularly noted, and although each is most closely associated with one of the three late Romantics, the three modes appear in one form or another, at one time or another, in all of these poets, and even occasionally in the early Romantics. The descriptive terms I am using here to set forth these distinctions are appropriated from the language of critics who have been largely hostile toward the work of the later Romantics. (115-16)
While Epipsychidion's subject is supposedly love, McGann is implying that it is not as simple as that, that there is a political dimension to the poem, one that suggests that love and poetry can be used as primary, pragmatic forces that can change the world through either aesthetic experiences or, or by using aesthetics as an allegorical means of suggesting what is possible. I think McGann's summary on the differences between the two generations of romantic poets is incredibly helpful, but I also think we should pay attention to potential aberrations to be found in the first-generation romantics, such as the political agenda within Wordsworth's Preface to the Lyrical Ballads (to take away the artificiality of poetic diction in order to make poetry more accessible to the general population), and Coleridge's insistence that Shakespeare had an intentional "design," which could be viewed as a means to make Shakespeare more accessible to readers as an artist and human, not some divine mystic who relied without hesitation on unconscious, free associations.
And although McGann uses the above passage to demonstrate the visceral, sensational, social, and political nature of the later romantic poets, we must pay attention to the "annihilation," an important word in the passage, which I cannot help but read as a negative consequence of a complete union, whether Shelley intended it to be read negatively or not. True, his "woe" at the end seems to be about his inability to "annihilate" a sense of self. If the poem were to continue, are we to imagine a more retrospective, contemplative, Wordsworthian verse?
McGann, Jerome. The Romantic Ideology: A Critical Investigation. Chicago: U of Chicago P, 1993.