For whence did Dante take the materials for his hell but from this our actual world? And yet he made a very proper hell of it. And when, on the other hand, he came to the task of describing heaven and its delights, he had an insurmountable difficulty before him, for our world affords no materials at all for this. Therefore there remained nothing for him to do but, instead of describing the joys of paradise, to repeat to us the instruction given him there by his ancestor, by Beatrice, and by various saints. But from this it is sufficiently clear what manner of world it is.
