The sinners of circle seven, round one, were violent against their neighbors. Their punishment was to be cast in a river of boiling blood and the deeper they were the more blood thirsty they had been in life.
Archetypes of this round could be found in the river filled with boiling blood. Normally, rivers are filled with water which can represent purity. The reason Dante could not have the sinners basking in a river filled with water is because the sinners were not pure, they were vile. Dante references great leaders in history by stating, "Here they pay for their ferocity./ Here is Alexander. Here is Dionysius,/ who brought long years of grief to Sicily." (114). He talks about Alexander the Great because he killed many people in his time and he was in one of the deepest parts of the river. The sinners of this round were bloodthirsty in life and in death they must bask in the blood they spilled.
The idea that the sinners are in a river represents human life and time passing. It is very straight forward, implying that the time they spent as humans they were ignorant and murdered their neighbors. Dante openly admits their ignorance when he says, "Oh ignorant, self-seeking cupidity/ which spurs us so in the short mortal life/ and steeps us so in all eternity!" (112). Here Dante talks about how ignorant decisions from short mortal life can hurt one for all eternity. The sinners in this round were bloodthirsty and rash. The boiling aspect of the blood can mean many different things. It could represent passion or a murder out of lust, it could also represent haste or a quick decision to commit murder, or it could represent anger which would be intentionally murdering someone you were angry at. The sinners were damned in all eternity in a river filled with boiling blood, to forever absorb the blood others spilled because of them.