Commentary Par II 64-148

See Russo (Russ.1971.1), pp. 103-58, 161-208, for an impassioned defense of the poetic qualities of such lengthy and ostensibly 'scientific' or 'philosophical' passages as this one, which he links with the only slightly shorter lesson in embryology offered up by Statius ([Purg XXV 37-108]).  For a careful study of the central theological and scientific issues here and the history of their reception among Dante's critics, see Vasoli (Vaso.1972.1).  A summary of this lengthy argument may be found in Grandgent; see DDP Singleton.Paradiso.II.52-148.  And for an immensely helpful basic bibliography on Dante in relation to the various sciences that make their presence felt in the poem, see the extended note by Simon Gilson ({ Gils.2001.2}), pp. 58-65.  For a useful review of some current writing on Dante's knowledge and use of the sciences, with bibliography, see Ledda (Ledd.2001.1).