Metaphor Analysis

Dante fills The Divine Comedy with hundreds of metaphors.  Only a close reading of the poems' "Notes" will give readers fair insight into the elaborate and complex metaphors, and metaphorical systems, employed by Dante.  Additionally, Dante scholars still disagree on many points related to the symbolism and true meaning of specific details in Comedy.  Thus, the following metaphor analysis touches only on overarching symbolism rather than any discrete aspects of Dante's metaphorical universe.
Numerology: Readers must pay close attention to Dante's use of numbers in The Divine Comedy.  'Three' represents the Holy Trinity so any multiple of three holds special meaning.  Thirty-three cantos make up each poem, Inferno, Purgatorio , and Paradiso, so the entire Comedy concludes in ninety-nine cantos.  However, just as Virgil refuses to utter the name of God in the unholy realm of Hell, so too does Dante refuse to represent the Infernowith a holy number of cantos.  Thus, Dante adds a thirty-fourth canto to Infernothat makes it the only imperfect part of his trilogy.  Readers must also note the use of numbers in smaller details throughout Comedy including: nine circles of Hell, seven terraces of Purgatory, nine spheres of Heaven, the description of the procession in the Earthly Paradise, and the description of the Rose in the uppermost region of Heaven.
Opposing Physical Sensations: As a mortal attempting to describe the mysteries of Heaven and Hell in a manner to which his contemporaries can relate, Dante uses opposing physical sensations (sight, smell, and sound) to convey his experiences.  Light and dark represent good and evil in all three realms such that overwhelming darkness fills Hell while Dante finds himself blinded by the brilliant lights in Heaven.  The vile stench of Hell increases the agony of the sinners in Hell while sweet-smelling flowers welcome Dante as he enters Earthly Paradise.  Thunder and the shrieks of tormented sinners compound the punishment faced by the underworld shades while spirits sing beautiful hymns throughout Purgatory and Heaven.
Just Punishment: The punishment assigned to the sinners in Hell represent their sins on Earth.  For example, a person who was a Flatterer-overly concerned with physical beauty-spends eternity immersed in excrement.  Thieves spend eternity running from reptiles that overtake their bodies and turn them into ash, stealing their forms just as the thieves had stole things that belonged to others on Earth.  With this structure of Hell, Dante intends to warn readers that while they may enjoy their sinful ways on Earth, they will find themselves tortured and tormented by their sins after they enter Hell.
Just Repentance: Like the sinners in Hell who must relive their sins on Earth, the spirits in Purgatory must repent in ways analogous to the sins that they committed on Earth.  For example, the Slothful must run feverishly about the Fourth Terrace while they sing hymns and cite examples of people who lived virtuous lives without sloth.