If Sleep and Death be truly one, And every spirit's folded bloom Thro' all its intervital gloom In some long trance should slumber on;
Unconscious of the sliding hour, Bare of the body, might it last, And silent traces of the past Be all the colour of the flower:
So then were nothing lost to man; So that still garden of the souls In many a figured leaf enrolls The total world since life began;
And love will last as pure and whole As when he loved me here in Time, And at the spiritual prime Rewaken with the dawning soul.
It's time for another extended metaphor, so get ready:
If death is like sleep, the speaker muses, then maybe the spirits of all dead people are just sleeping for a long time in a trance.
He envisions these spirits as flowers, which are "folded blooms." So, Tennyson is using the image of flowers that fold up during the night and then open up into blooms during the day to represent the spirits of the departed.
Such a scenario would mean no living memories would be lost when someone dies.
Tennyson here imagines a sort of "garden of souls" made up of napping, happy little flowers that exist outside of time. This is a nice, peaceful image of nature (compared to some of the more hostile ones we've seen so far, like the yew tree and the sea).
After they die, people would just sleep—with all their memories intact—until they awaken to life-after-death. He represents this with the "dawning soul."
The love between Tennyson and Arthur wouldn't be lost after all.