"'The Divine Comedy' begins in a shadowed forest on Good Friday in the year 1300. It proceeds on a journey that, in its intense recreation of the depths and the heights of human experience, has become the key with which Western civilization has sought to unlock the mystery of its own identity. Allen Mandelbaum's astonishingly Dantean translation, which captures so much of the life of the original, renders whole for us the masterpiece that genius whom...