The Divine Comedy is not a comedy in the modern sense, since few readers have found much humor in the poem. It is called a comedy, as opposed to a tragedy, because it has a happy ending, concluding with Paradise, the love of God, and the possibility of salvation.

This is the great theme of The Divine Comedy. Dante begins by exploring Hell, learning by example after hideous example how not to behave if he is to achieve his objective. The main theme of the Inferno is the horror of damnation, and how to avoid it, just as Purgatorio shows how the pure love of God may be corrupted by humanity. In context, however, these themes contribute to the greater, overarching themes of salvation and divine love.

The Divine Comedy is the most didactic of epics. The poem's great objective is to teach the reader how to achieve salvation and free himself from sin. Because Dante provides example after example, particularly in the Inferno, which can be read as a compendium of sin and sinners, the reader is presented with something like an academic course in all the ways humanity can be found wanting. The use of contrapasso, in which the punishment either resembles or contrasts with the sin, serves to emphasize the nature of the transgression for didactic purposes.