Landon

“Dante’s notions of sin are shaped largely by the writings of St. Thomas Aquinas. In his famous Summa Theologiae, Aquinas argues that any evil action or sin is a form of self-destruction. He assumes that human beings have a nature that is supposed to be rational and good. Aquinas conceives of this nature, that of the rational animal, as being created by God specifically to pursue goodness, more specifically, the virtues. When a human being departs from this natural purpose, she injures herself, for she does what she was not intended to do. She wars against herself and her nature. Why does Aquinas hold this peculiar view of sin? One reason is because he accepts Boethius’ assertion that goodness and being are convertible. In other words, anything that exists has some goodness in it because God made it. And no matter how marred or broken or sinful that being is, it still maintains some goodness so long as it exists. According to this view, no one, not even Lucifer encased in ice at the bottom of Dante’s Inferno, is wholly evil. Evil can only feed off of goodness like a parasite; if all the goodness of a creature were eliminated, the creature in question would no longer exist.”
― Sylvain Reynard, Gabriel's Inferno