Dante's Christian Astrology, by Richard Kay languages Latin works Abraham Ibn Ezra Albumasar Alcabitius Commedia Dante's Christian Astrology Guido Bonatti Haly Abenragel John of Seville Liber novem iudicum Michael Scot Nine astrological handbooks Paradiso Ptolemy Timaeus dates 1265-1321 people Abraham Ibn Ezra Albumasar Alcabitius Dante Alighieri Haly Abenragel John of Seville Michael Scot Ptolemy places Paradise Philadelphia University of Pennsylvania