According to Catholic doctrine union with God is the basis of happiness, and separation from God is the greatest punishment for a human being. What enables us to become closer to God is our free will and our reasoning power, when we loose those things we have no hope of achieving happiness. Violence is a very clear demonstration of the loss of these two faculties of the intellect, the way Dante depicts the souls of the seventh circle of Hell accurately portrays this idea.

Rooted in anger violence is controllable by will power, but its particular nature, which goes back to animal instincts, account for the loss of control experienced by an enraged person. This animal origin of violence is most noticeable in the seventh circle of Hell:

"And at the edge, along the shattered chasm,
there lay stretched out the infamy of Crete:
the son conceived in...