The only character besides Dante to appear all the way through Inferno, Virgil’s ghost is generally taken by critics to represent human reason, which guides and protects the individual (represented by Dante/Everyman) through the world of sin. As befits a character who symbolizes reason, Virgil proves sober, measured, resolute, and wise. He repeatedly protects Dante from hostile demons and monsters, from Charon to the Centaurs. When he appears powerless outside the gates of the city of Dis in Canto VIII, his helplessness appears very ominous, signifying that Lower Hell offers far darker dangers than Upper Hell.
Virgil’s reliance on the angelic messenger in this scene also symbolizes the fact that reason is powerless without faith—an important tenet of Dante’s moral philosophy and one that marks Inferno as a Christian poem, distinct from the classical epics that preceded it. In the fullest sense of the word, Virgil acts as Dante’s guide, showing him not only the physical route through Hell but also reinforcing its moral lessons. When Dante appears slow to learn these lessons—such as when he sympathizes with sinners or attempts to remain too long in one region of Hell—Virgil often grows impatient with him, a trait that humanizes this otherwise impersonal shade.
Dante the character and Dante the poet seem to regard Virgil differently. Dante the character regards Virgil as his master, constantly swearing his admiration for, and trust in, him. Dante the poet, however, often makes use of Inferno to prove his own poetic greatness in comparison to the classical bards who preceded him—including Virgil, who lived more than a thousand years before Dante.
In Dante’s time, Virgil, the author of the Aeneid, was considered the greatest of the Roman poets. As with many of his other classical and mythological appropriations, Dante’s inclusion of Virgil in his poem denotes both an acknowledgment and appreciation of classical tradition and, to some degree, a form of bragging on Dante’s part: for while he respects Virgil enough to include him in his work, he also suggests that his poem subsumes Virgil entirely.