VIOLENCE
"...God hates it most"

As we approach this destination, we find there are 3 inner circles inside each other, "...since three ways is violence shown: To God, ourselves, or neighbors may be done Violence..." "Violence against others" seems to be self-explanatory, but for the other forms of violence, see the details below:

1. For those "...to God may violence extend...", this violence may through "heart denial and by blasphemy."
2. For those who are "violent against himself", it may be suicide, or it may simply be "...'gainst his goods; therefore without avail." The people found in these circles are also disloyal to themselves, and includes those "...who pursue Magic, false coining, theft, and simony [selling of religious articles], Pimps, [and] barrators [those who neglect their employees]" 
3. "We come ere long Down to the river of blood where boiling lie." This is where, "All who by violence work others wrong..." Around this river of blood, "Centaurs were running who were armed with bows, As if they hunted on the earth again." My master informs me that Alexander the Great, Attila the Hun and Dionysus I of Syracuse, the cruelest Greek tyrant who ever lived, are among the ones in the river of blood. 
4. Next we move into the inner-circle of this circle where we we  "...within a forest drew...Not green the foliage, but of dusky hue; Not smooth the boughs, but gnarled and twisted round; For apples, poisonous thorns upon them grew." These trees were preyed upon by the Harpies, winged creatures who pecked at their branches. "I stretched forth my hand And plucked a tiny branch from a great thorn. ‘Why dost thou tear me?’made the trunk demand. When dark with blood it had begun to turn, It cried a second time: ‘Why wound me thus? Doth not a spark of pity in thee burn? Though trees we be, once men were all of us; Yet had our souls the souls of serpents been Thy hand might well have proved more piteous.’ I recoiled; I didn't know that I had broken off a limb of a person! Those who inflicted "violence on themselves" had caused ME to injure THEM!
5. And lastly, we enter the inner-most circle. "O’er all the sand, deliberate and slow, Broad open flakes of fire were downward rained...on the host they fell." Those who committed violence against God suffered rains of eternal fire from Heaven...