There are many discussions about the use of the number "three" and its various symbolic uses. But seldom is there any discussion of the number "two." However, looking at the beginning of Hell Proper and the ending of Hell Proper would demonstrate two contrasting pairs forever bound together.
Canto V, therefore, enters Hell Proper, which may be said to begin with the second circle, because here Minos is seated as the judge to determine where the sinners before him are sent for punishment. Thus, Hell Proper begins with Canto V and the punishment of Francesca and Paolo.
In contrast, Hell Proper closes with another pair — Count Ugolino and Ruggieri — locked in an embrace, with Ugolino gnawing on the brainpan of Ruggieri. Even though the final canto presents the horrors of being exposed to Satan itself, it is in the ending of Canto XXXII, where Dante first sees this gruesome pair, and in Canto XXXIII, where their story is told with such power and perfection, that Dante provides the thematic ending of Hell Proper.
Thus, Hell Proper begins with love joining two delicate souls together throughout eternity. In contrast, Hell Proper may be said to end with hate joining two violent, vicious men together throughout eternity.
Paolo and Francesca are bound together in a type of embrace and in a love that knows no bounds — a never-ending love that will continue throughout all eternity.
The other pair, Ugolino and Ruggieri, are at the bottom of Hell and are also bound together through a hate that can never be satiated — if anything, Ugolino's hatred will increase throughout all eternity.
