Matthew Pearl said this quote
“ ...It is the one time Dante calls such explicit attention to the idea of contrapasso-a word for which we have no exact translation, no precise definition in English, because the word in itself is its definition... Well, my dear Longfellow, I would say countersuffering ... the notion that each sinner must be punished by continuing the damage of his own sin against him... just as these Schismatics are cut apart... ”