1. The sins most severely punished are the sins of treason. The traitors are in the last cycle of hell, known as Lucifer's Frozen Abyss. For Dante, any type of betrayal represented the maximum of human corruption, moreover, it is likely that in this cycle, Dante refers to Florentine traitors who betrayed his homeland.
2. Dante's Inferno reveals many elements of medieval culture, perhaps the strongest of them, is the need for devotion, placing the human being as someone doomed to hell and being able to escape it only by devotion to God.
3. Dante's hierarchy of hell is something very well constructed and developed, it is not for nothing that this book is considered one of the most important of humanity. However, I do not agree with the hierarchy established in Dante's narrative. That's because the hierarchy separates sins in terms of severity. For me, there are no more or less serious sins. All sins carry the same weight, so they must all be subject to the same type of punishment and rejection.
