Commentary Par II 112-114

Going back, in thought, to the Beginning, the Empyrean, Beatrice turns her attention to the Primum Mobile, the ninth sphere, where nothing may be seen but where all the powers that course through the universe have their origins in space and time.  See the poet's earlier treatment in Convivio (Conv.II.xiv.15): 'For, as the Philosopher says in the fifth book of the Ethics, "legal justice disposes the sciences for our learning, and commands that they be learned and taught in order that they not be forsaken"; so with its movement the aforesaid heaven governs the daily revolution of all the others, by which every day they all receive and transmit here below the virtue of all their parts' (tr. R. Lansing, italics added).