In his introduction to Dante’s Inferno, Lino Pertile, an Italian linguist and Professor of Romance Languages and Literature at Harvard University, writes:
The exploration mapped in the Inferno is a voyage through the immense historical archives of the world’s evils, ordered according to type and severity in the subsoil of the dark forest. On the surface of the earth, evil can manifest itself in disorderly ways and in complex forms that do not always allow themselves to be fully fathomed by the eyes of the living. In Hell, however, the deeply rooted motivations as well as the extreme consequences of human actions are revealed. Outward appearances have no place here; every choice appears in its barest, most essential truth, and is judged as such. Evil is without remedy, truce, or hope of relief; it has no other boundary than its everlasting present. One cannot even say that evil triumphs on its own ground, since what triumphs over it is Divine Justice, which reduces everything to order and employs evil against itself.
— The Cambridge Companion to Dante, edited by Rachel Jacoff