The three great English poets who are also fundamentally mystical in thought are Browning, Wordsworth, and Blake.  Their philosophy or mystical belief, one in essence, though so differently expressed, lies at the root, as it is also the flower, of their life-work.  In others, as in Shelley, Keats, and Rossetti, although it is the inspiring force of their poetry, it is not a flame, burning steadily and evenly, but rather a light flashing out intermittently into brilliant and dazzling radiance.  Hence the man himself is not so permeated by it; and hence results the unsatisfied desire, the almost painful yearning, the recurring disappointment and disillusionment, which we do not find in Browning, Wordsworth, and Blake.

In our first group we have four poets of markedly different temperaments—­Shelley intensely spiritual; Rossetti with a strong tinge of sensuousness, of “earthiness” in his nature; Browning, the keenly intellectual man of the world, and Patmore a curious mixture of materialist and mystic; yet to all four love is the secret of life, the one thing worth giving and possessing.

Shelley believed in a Soul of the Universe, a Spirit in which all things live and move and have their being; which, as one feels in the Prometheus, is unnamable, inconceivable even to man, for “the deep truth is imageless.”  His most passionate desire was not, as was Browning’s, for an increased and ennobled individuality, but for the mystical fusion of his own personality with this Spirit, this object of his worship and adoration.  To Shelley, death itself was but the rending of a veil which would admit us to the full vision of the ideal, which alone is true life.  The sense of unity in all things is most strongly felt in Adonais, where Shelley’s maturest thought and philosophy are to be found; and indeed the mystical fervour in this poem, especially towards the end, is greater than anywhere else in his writings.  The Hymn to Intellectual Beauty is in some ways Shelley’s clearest and most obvious expression of his devotion to the Spirit of Ideal Beauty, its reality to him, and his vow of dedication to its service.  But the Prometheus is the most deeply mystical of his poems; indeed, as Mrs Shelley says, “it requires a mind as subtle and penetrating as Shelley’s own to understand the mystic meanings scattered throughout the poem.”

Shelley, like Blake, regarded the human imagination as a divine creative force; Prometheus stands for the human imagination, or the genius of the world; and it is his union with Asia, the divine Idea, the Spirit of Beauty and of Love, from which a new universe is born.  It is this union, which consummates the aspirations of humanity, that Shelley celebrates in the marvellous love-song of Prometheus.  As befitted a disciple of Godwin, he believed in the divine potentiality of man, convinced that all good is to be found within man’s own being, and that his progress depends on his own will.