In Inferno, the most basic and most forgivable category of sin is incontinence, or a lack of self-control. The incontinent sinners constantly indulge their impulses... whether its for more ice cream or more sex.
The core of the incontinents’ wrongdoing lies in their failure to use their God-given minds to judge their actions as good or evil. Because they don't think and act on their feelings, the incontinent sinners deny their human civility. This is why Dante often paints them using animal imagery. In the sinners’ defense, however, incontinence is instinctive and primitive; lust, hunger, and wrath are universal urges, felt by all human beings.
In Dante’s Inferno, the text suggests that the incontinent sinners behave in a more bestial fashion than a human one.
If Nature is an expression of God’s will and the incontinent sinners only follow their natural instincts, then the incontinent sinners did not really sin.
In Inferno, Nature’s author is God himself and anything described as natural has to honor the Divine. So, the most unnatural scenes occur in the circles of heresy and violence, where familiar or pastoral landscapes become distorted in some huge way.
The violent, especially those who have sinned against nature, demonstrate this best—in the image of reproduction. Usurers gain from the unnaturally speedy accumulation of money, which requires no coupling but simply produces more and more in and of itself. Heretics, in denying man’s immortal soul, reject one of the basic truths. Heresy and violence are considered worse sins than incontinence.
To support the idea that violent sinners move against the natural order, the environs of the Seventh Circle feature natural settings perverted in one fundamental aspect.
All of the guardians in the Seventh Circle juxtapose the bodies of two different species to reflect the perverted nature of the sinners.
While Inferno's author denounces fraud as contradicting the truth, his contempt for it runs way deeper than that. The root of fraud is linguistic sin and because man’s unique gift is language, human beings seem particularly susceptible to fraud.
As one of the major unifying bonds in society—uniting individuals and facilitating communication—language holds a high status in Dante’s eyes. The fraudulent, by corrupting language, threaten to compromise the cohesiveness of society. Unlike incontinence and violence, which affect only the agent or his victim, fraud has the ability to deceive whole communities of people—even institutions like the Church and entire cities like Florence.
Fraud is considered a more wicked sin than incontinence or violence because it compromises universal human connections like language and money and has the ability to dupe whole communities of people, instead of harming only the individual committing the fraud.
Based on Geryon’s appearance and the metaphorical language with which Dante surrounds his description, the beast clearly represents the sin of fraud.
In Dante’s Inferno, justice is not merely cruel and unusual punishment designed to elicit cheap shock from onlookers (although it does that, too). Inferno portrays God’s justice as springing from primal love, and thus is conditioned with compassion, however difficult it may be to recognize. Still, the point of justice is that transgressors must get their just desserts.
Dante ensures this happens using the concept of contrapasso, which translates literally as "counter-penalty." Here, sinners are punished according to the nature of their sin, so that their punishment fits their crime. Some sinners literally become the embodiment of their sins while others become victims in the afterlife of the crimes they committed while living.
By condemning the virtuous souls in Limbo to eternal damnation, God does not hold people born before the life of Jesus Christ to the same standards as those who came after him.
In the Inferno, one’s punishment fits his crime, in a form of justice, contrapasso, that forces one’s sin to turn back on the sinner.
Language is king in Inferno... so it sucks even more to be punished by, say, having to blow bubbles of mud for all eternity. A product of the rational mind, language is considered by Dante to be a medium shared by all men that serves to unite them. As a uniquely human attribute, language—like man—is never defined as inherently good or inherently evil. Indeed, its moral standing is determined by the way in which it is used. Readers are never shown a definitively correct and moral speech.
The breakdown of Virgil’s "persuasive word" affects his language in the ensuing cantos and results in a marked lessening of his pride.
Although one’s idiosyncratic way of speaking can illustrate regional pride, for Dante and the sinners, individualized speech is a cause for shame.
As the only species of all God’s children bestowed with a rational mind, humanity (woo-hoo, humanity!)—according to Dante—is obligated to properly use its God-given gift responsibly. Dante calls this duty the "good of the intellect." All man’s works then should in some way be devoted to honoring nature or worshipping God.
Indeed, Inferno could be viewed as such a work, stemming from his own philosophy. Any works that deny God’s infallibility, pervert nature’s trends, or attempt to surpass man’s limits, are sinful. Man’s use of language is particularly subject to this "good of the intellect" ethos, since language is one of the primary expressions of man’s mind.
Because fraud involves a deliberate misuse of man’s mind, it is considered the wickedest of sins.
Despite Brunetto’s generous character and Dante’s warm reaction to him, Brunetto makes a potentially dangerous assertion that man’s only chance at immortality is through the survival of his works; this inherently denies man’s immortal soul.
Dante considers the quality of compassion—defined as having pity for another man’s suffering—an essential human trait. Sometimes Dante’s compassion for the sinners’ plights reaches such a depth that Dante himself seems to suffer with them.
Compassion in the Inferno often comes across as weakness and improper sympathy for an evildoer. But it is one of Dante’s most effective ways of creating a connection with the reader, appealing to his or her sense of pathos and ideas about human decency. In Hell, however, compassion can indeed mislead men into wrongly sympathizing with true villains. As the protagonist’s journey continues, he learns to harden his heart and to distinguish between various levels of sin.
Throughout the Inferno, Dante’s compassionate character renders him vulnerable to the sins surrounding him.
Although the alleged "noble sinners" initially arouse Dante’s sympathy, he grows less and less sympathetic as his journey continues.
Although love isn't frequently mentioned in the text of the Inferno, it is always in the back of the reader’s mind. Love’s single most surprising appearance comes at the threshold of Hell, where Dante learns that this place of punishment has been created from "Primal Love." Wait—what?
As Dante meets sinner after sinner and hears their pitiable stories, readers are encouraged to question—along with Dante—how a loving God could impose such pain on seemingly decent people. With his often sympathetic portrayals of sinners, Dante directly challenges the notion that Hell could have been created out of love. On a more mundane level, love—like language and matter—is considered one of the fundamental bonds that tie individuals together. When this bond is broken, many people can be affected and led into sin.
The portrayal of the noble sinners contests the idea that Love created Hell by emphasizing their virtue over their sin and eliciting readers’ sympathy for their eternal suffering.
Dante’s treatment of family members and father figures suggests that one’s love for his family should remain strong no matter what happens.
In Inferno, Hell is all about stasis, or an unchanging permanent state, on a number of levels. First, the very structure of Hell—a series of concentric circles—gives an impression of inescapability, since circles have no ends or edges and one can only continue tracing their arcs in a futile attempt to find a way out.
Secondly, sinners cling to their sinister ways and refuse to repent. In their refusal to change, they condemn themselves to an unending stream of punishment. When the protagonist finally does escape Hell and emerges on earth’s surface, the position of the sun in the sky seems not to have changed at all... giving the impression that no time has passed since he went to Hell and back.
As the levels of Hell deepen, the sinners within each successive circle become more entrapped and more immobilized; in a parallel vein, it becomes increasingly difficult for Dante to move forward through the Hell.
At the boundary between each circle, Dante experiences a period of paralysis, suggesting that Hell discourages movement and enforces stasis on its prisoners.
In the Inferno, sinners in Hell are totally preoccupied with achieving fame and commemoration among the living. The question of how a man is remembered after his death is a topic of serious discussion. The logic goes that if one’s memory fades or is forgotten amongst the living, one truly dies (maybe even from Hell).
Despite their crimes—or because of them?—the sinners are willing to exchange virtually anything for the protagonist’s agreement to carry news of their good names back to the living. Like every creature, man fears death, even after his body has expired.
The sinners’ obsession in speaking to Dante can be explained by their desire to inflate or rescue their reputations in the world above; for them, memory is their last hope of living freely.
By falsely promising to honor the sinners’ names, Dante does indeed sin, but such behavior is condoned because God sanctions it.