Human nature is presented in The Divine Comedy as fundamentally sinful. Since man's original ancestors, Adam and Eve, defied God and ate from the Tree of Knowledge, humankind has been mired in sin. In addition to this original sin, there are the sins committed by individuals. Such sins would include adultery, murder, simony—the buying and selling of church offices—and betrayal. All these sins and more are punished in Hell, which is depicted with such imagination by Dante in the Inferno.

And yet Dante's depiction of the sinners in Hell is by no means uniform. Some are shown to be more sympathetic than others. This is a recognition on Dante's part of the fundamental complexity of human nature as well as its innate sinfulness.

One of the most sympathetic characters that Dante the pilgrim encounters in Hell is Francesca da Rimini. She's there with her brother-in-law Paolo, with whom she had an affair. As punishment for their sins, Paolo and Francesca have been consigned to the second circle of Hell, which is reserved for the lustful.

When Francesca tells Dante why she and Paolo have been damned to Hell, Dante faints out of pity. From his reaction, we can observe that Dante's understanding of human nature—at least at this relatively early stage of his journey—shows a recognition of its complexity. Paolo and Francesca may be sinners, but they are still recognizably human all the same.

Dante’s The Divine Comedy has a wide range of characters with many different backgrounds and personalities. In order to discuss human nature throughout this long epic poem, consider what all of its human characters have in common, including the souls that were once human. All of these characters—regardless of their location in the three parts of Dante’s story—are subject to God’s law. To be human is to be bound to God’s order. Individuals can follow or transgress that order, but they all have to contend with the consequences.

Ignorance of God’s law as it is revealed in Christianity does not excuse a person from their obligation to it. For example, pre-Christian philosophers and poets end up in Limbo, a part of Hell without any actual punishment. While these figures did not choose to break any sacred laws, and are therefore not punished in a painful way, they were never baptized and therefore cannot enter Heaven. Just being human bound these Greek and Roman figures to those obligations. Their particular historical or cultural context does not make a difference. Their humanity transcends that context.

Dante carefully explains why each soul ended up in a particular part of Hell, Purgatory or Paradise. Being human carries a duty to God: people are responsible for their actions, they must avoid temptation, and act according to God’s design. He gives many examples of people giving into temptation, being tempted but not acting on it, and completely resisting temptation. In other words, he explains the consequences of each character’s unique set of motives and actions. Again, human subjecthood to God transcends the unique situation of each person. At the same time, humans are bound to God’s law but can also make choices. They are not controlled by God but are autonomous beings subject to their own choices, and can ultimately be damned or saved. Human nature is both a burden and a potential blessing. It can bring people closer to God or cast them away from Him.

The Divine Comedy reveals a lot about human nature, and it's difficult to touch on every single theme, desire, and emotion that Dante's work describes. However, if we look at the central goal of the story (to achieve spiritual atonement through a harrowing journey), we see one major part of human nature revealed: the desire for salvation. When the poem begins, Dante is wandering in a dark wood, apparently lost, directionless, and out of ideas. Somehow, his life seems to have gone off track, and he seems clueless when it comes to finding direction. The rest of the poem is Dante's quest to find salvation from this predicament, and the many trials and and tribulations that he weathers are all a necessary part of his efforts to leave behind the dark wood of his life.

Of course, in touching on humans' desire for salvation, the poem is first and foremost talking about Christian salvation; the poem is a Christian journey and is informed by classic Christian themes and philosophies. However, in drawing on mythology, literature, and history as well, Dante opens up his poem to being more than just a poem for Christians. Thus, though the salvation in the poem is primarily Christian, it's still possible to also see the theme in non-spiritual terms: at some point in life, no matter who you are, it's common to feel lost and confused and unable to find your way. In such situations, people yearn for salvation of one kind or another. Therefore, Dante's exploration of the search for salvation becomes a truly universal quest that any person could relate to.