Cerberus guards Circle III, and as in mythology, he requires a concession for each of his three mouths (this time the foul mud of the circle suffices) before he permits passage. With his constant hunger, Cerberus is a fitting guardian for the circle of Gluttons, who transformed their lives into a continual feast and did nothing but eat and drink, for which they must now lie like pigs in the mire.
Cerberus should be familiar to the readers of Homer and Virgil. In those works Cerberus had to be placated with some delicacy in each of its mouths. In contrast, Virgil fills each mouth with some dirty slime which is more fitting for the guardian of the gluttons.
In the intellectual progression down through Hell, Dante moves the readers from the circle of lust, a type of sin that was mutual or shared, to the third circle, which includes sin performed in isolation. The glutton is a person with an uncontrolled appetite, who deliberately, in his or her own solitary way, converted natural foods into a sort of god, or at least an object of worship. Therefore, the glutton's punishment is a reversal, and instead of eating the fine delicate foods and wines of the world, he or she is forced to eat filth and mud. Instead of sitting in his or her comfortable house relishing all the sensual aspects of good food and good wine and good surroundings, he or she lies in the foul rain.
Aside from brief mention in earlier cantos, Canto VI includes Dante's first political allusion, which takes the form of an outburst from Ciacco. The voice is Ciacco's, but the words are Dante's. Ciacco's prophecies are the first of many political predictions that recur in the Divine Comedy and especially in Inferno. Because the imaginary journey takes place in 1300, Dante relates as prophecies events that already occurred at the time he composed the poem.
Note that the souls in upper Hell want to be remembered on Earth, while the souls in lower Hell are reluctant to even give Dante their names.
