The only thing that unites them in idea, and in the end, is that both have proceeded from the creative joy of God.
Of course this way of thinking permits of the things of Nature being used to illustrate the doings, thinkings and character of man; and in none of his poems is such illustration better used than in _Sordello_.
There is a famous passage, in itself a noble description of the opulent generativeness of a warm land like Italy, in which he compares the rich, poetic soul of Sordello to such a land, and the lovely line in it, And still more labyrinthine buds the rose, holds in its symbolism the whole essence of a great artist's nature.

I quote the passage.

It describes Sordello, and it could not better describe Italy: Sordello foremost in the regal class Nature has broadly severed from the mass Of men, and framed for pleasure, as she frames Some happy lands, that have luxurious names, For loose fertility; a footfall there Suffices to upturn to the warm air Half-germinating spices; mere decay Produces richer life; and day by day New pollen on the lily-petal grows, And still more labyrinthine buds the rose.
That compares to the character of a whole country the character of a whole type of humanity.

I take another of such comparisons, and it is as minute as this is broad, and done with as great skill and charm.
Sordello is full of poetic fancies, touched and glimmering with the dew of youth, and he has woven them around the old castle where he lives.
Browning compares the young man's imaginative play to the airy and audacious labour of the spider.

He, that is, Sordello, O'er-festooning every interval, As the adventurous spider, making light Of distance, shoots her threads from depth to height, From barbican to battlement: so flung Fantasies forth and in their centre swung Our architect,--the breezy morning fresh Above, and merry,--all his waving mesh Laughing with lucid dew-drops rainbow-edged.
It could not be better done.