Those who do not love living things do not love God or Man, as the Ancient Mariner found to his cost. But because some Greek poet loved the nightingale, he created from her the human figure of Philomela, and by doing so passed from love into vision, from a sensitive reaction to nature into the intelligent form of civilized human life, or Paradise. The story of Philomela is not a fantasy suggested by the nightingale, but a vision of the fall of the original human nightingale into its present natural shape. Blake says:
Think of a white cloud as being holy, you cannot love it; but think of a holy man within the could, love springs up in your thoughts, for to think of holiness distinct from man is impossible to the affections.*
But if the poet can see the world in a grain of sand, it is because he already has that archetypal vision of “All that Exists,” of which everything he sees is a form or image. All Blake’s poetry is related to his particular view of this vision, that “Central Form composed of all other Forms” . . . Within the huge framework of this central form, certain states of the human mind that created it inevitably appear and take on human lineaments, just as a pantheon crystallizes from a religious vision. Blake’s characters are the “Giant forms” that religions worship as gods and artists visualize as “organized men.”
* from Blake’s marginalia on Swedenborg