In both theme and placement, Book VI, which many consider to be Virgil's greatest literary accomplishment, is of central importance to the development and the ultimate meaning of the Aeneid. Here, just after the Trojans land permanently in Italy, Aeneas descends to the underworld for his long-anticipated rendezvous with Anchises's ghost, who reveals Rome's future to his son.
Virgil's imagination and intellect create an otherworldly vision that invites readers to accept it as a symbolic statement concerning the nature of life after death. The possibility of reincarnation, which provides a philosophical basis for the pageant of souls about to be reborn as personages in Roman history, fuses Virgil's speculations on the afterlife with the national theme that lies at the heart of the epic and is its whole reason for being.
The essential philosophical message of Book VI is that the soul, contaminated by its association with the body during mortal life, undergoes purgation after death. Passing on to Elysium, it remains there for a thousand years and is then reborn into the world. The cycles of death, purgation, and rebirth continue until, purified at last, the worthy soul ascends to a state of "fiery energy from a heavenly source." A few exceptionally virtuous souls — like that of Anchises — are free from having to submit to this cyclical process, and they remain in Elysium. Although Virgil does not say so explicitly, presumably they too will ascend eventually to the nebulous Roman spiritual realm.
