On page 228 we read: "Again we find Blake's most visionary, most living figure of Los, his atributes and his operations, deeply rooted in a traditional metaphysical theme. Blake's imagination was at all times ready to be kindled by such themes, often in themselves abstract and recondite; and from such germinal ideas we can follow the growth and ramifications of his myths. For Blake no idea seemed to fully exist until it found expression in being, and being in action. For him there were no abstractions; every abstraction he saw (and personified in the figure of Urizen) as a mode of being.
Thus Blake, in the myth of Los creating the sun of nature, re-creates Swedenborg's doctrine of 'influx'. Spiritual light and fire descend from the spiritual world to be molded by Los into the orb of the natural sun:
Song of Los Plate 8, Copy A
4: And first from those infinite fires The light that flow'd down on the winds lie siez'd; beating incessant, condensing The subtil particles in an Orb. 5: Roaring indignant the bright sparks Endur'd the vast Hammer; but unwearied Los beat on the Anvil; till glorious An immense Orb of fire be fram'd 6: Oft he quench'd it beneath in the Deeps Then surveyd the all bright mass. Again Siezing fires from the terrific Orbs He heated the round Globe, then beat[,] While roaring his Furnaces endur'd The chaind Orb in their infinite wombs 7: Nine ages completed their circles When Los heated the glowing mass, casting It down into the Deeps: the Deeps fled Away in redounding smoke; the Sun Stood self-balanc'd. And Los smild with joy. He the vast Spine of Urizen siez'd And bound down to the glowing illusion 8: But no light, for the Deep fled away On all sides, and left an unform'd Dark vacuity:" Book of Los, Plate 5, (E 94)