The epigraph from Dante's Inferno consists of lines spoken by Guido da Montefeltro, Lord of Urbino, who is being punished for fraud, and in it, he mistakenly assumes that Dante, like him, is dead and that he may therefore confess his misdeeds without fear that his confession will ever reach the world of the living.
"The Love Song of J. Alfred Prufrock" may also be seen as a confession. Prufrock is timid and ineffectual rather than evil. However, like Montefeltro, he has spent his life being dishonest and, also like Montefeltro, he believes that his confession will never have any influence in the world, since he seems to be talking to himself about feelings he never shares with anyone else.
Prufrock's dishonesty is less serious than Montefeltro's. Most, if not all, of the harm he inflicts is on himself. However, this fraud still has the power to keep him trapped in a hell of his own making. In Prufrock's case, the punishment is not merely imposed to be apposite for the crime, like the punishments in the Inferno. It is actually an organic part of the crime, as he is forever trapped in silence and loneliness by his own inauthenticity.