Dante was a fierce Guelf supporter and stood opposed to the Popes holding the political power in Italy. In Canto 19 of Inferno he states that the Pope Nicholas III is already in Hell, and he is awaiting the arrival of Boniface VIII and Clement V:
And he cried out: “Dost thou stand there already,
Dost thou stand there already, Boniface?
By many years the record lied to me.Dante Alighieri
By the time Dante wrote Divine Comedy, his worst enemy, Pope Boniface VIII, was still alive, as well as Pope Clement V. Therefore, Dante in advance and not by chance determined for them a place among the simonists in the eighth circle of Hell. However, why exactly did Dante put these three Popes into Hell? What crimes did they commit to be placed this far in the pits of the Underworld?
Upon seeing the sinners of the 4th chasm of 8th circle – those who practiced astrology and divination – Dante weeps and grieves their fate. Virgil, however, is not pleased with such reaction, and reprimands Dante, claiming that they were given justice for their sins. The poet specifically points out four most famous diviners: Amphiaraus, Tiresias, Arruns, and Manto, relaying their stories to Dante and making him promise that he will tell the truth about them in his poem. For Dante, this is a first occurrence that he feels remorse and pity for the sinners, as previously, everybody he met in Hell were either his enemies or significant historical or mythological figures. Moreover, Virgil, who usually demonstrated a rather neutral or even sympathetic behavior towards sinners, in this Canto, shows strong aversion towards fortune tellers. This is, perhaps, due to the fact that their sin is a direct offense to God – only He can know the future, and no mortal soul should claim to see ahead of His will.
Reference
Alighieri, D. (2000). The Divine Comedy. (A. Mandelbaum & S. Botticelli, Trans., E. Montale & P. Armour, Eds.). David Campbell Publishers.