What universal theme does this excerpt represent

Which is a theme in “young goodman brown” ?

This excerpt is from “the poet” by alfred, lord tennyson. the poem describes a poet's consciousness and perception. which three lines suggest the richness of a poet's thoughts? thus truth was multiplied on truth, [the world like one great garden show'd,] and thro' the wreaths of floating dark upcurl'd, rare sunrise flow'd. [and freedom rear'd in that august sunrise] her beautiful bold brow, when rites and forms before his burning eyes melted like snow. [there was no blood upon her maiden robes] sunn'd by those orient skies; but round about the circles of the globes of her keen eyes and in her raiment's hem was traced in flame wisdom, a name to shake [all evil dreams of power--a sacred name.] and when she spake, [her words did gather thunder as they ran,] and as the lightning to the thunder which follows it, riving the spirit of man, making earth wonder, so was their meaning to her words. no sword of wrath her right arm whirl'd, [ but one poor poet's scroll, and with 'his' word] she shook the world.

Where is grendel? where does he go? what makes him go? will he return? what will he be when he returns? what do his origins and destinations have to do with his character?