She begins by demonstrating that Dante’s belief involves a true dilemma (an either/or) and proceeds to reduce either term to an absurdity, offering in evidence practical observations of an eclipse and an experiment she suggests to Dante. As noted above, she then explains the phenomenon by the mystic nature of the Primum Mobile.

 

93. reflected: Dante says “rifratto” (refracted). The physics of his time did not distinguish between reflection and refraction.

 

94. instance: A technical term (“instanza”) of Aristotelian and Scholastic logic signifying “counter-proposition.” Dante’s figure treats the instance as a trap from which one must escape with the aid of experiment.

 

96. art: Learning. See Inferno, XI, 97-105. In Dante “art” signifies the skills, the crafts, and all the methods by which man understands and wins control over nature. It is always distinct from the higher knowledge of faith.

 

97-105. THE EXPERIMENT. Dante assumes in this experiment that the heavenly bodies are highly reflective surfaces. Thus by shining a light into three mirrors, two equidistant from him and one further back, and noting (though the size of the remoter image is smaller) that the brightness of all three is equal, he seems to argue that light of equal intensity is equally brilliant from whatever distance it is reflected. The argument is ingenious but any reader interested in the rudiments of science will be able to offer his own refutation of the experiment when its conclusions are applied to heavenly bodies at astronomic distances as seen at varying angles through a varying atmosphere.

 

108-109. cold and color: Both the cold and the whiteness are removed from the ground. so you, stripped in your mind: So Dante, the cold and color of error stripped from his mind, will be flooded with the living light (like the fructifying light and heat of returning Spring) of the truth.

 

112. the heaven of peace beyond the sky: The Empyrean. I have had to take liberties here. A literal rendering would be: “within the heaven of the divine peace.”

 

113. a body: The Primum Mobile. Since the Empyrean (which lies beyond) is beyond space, the sphere of the Primum Mobile contains all of the universe. Taking its power from the all-encompassing Godhead (the Empyrean), it gives rise to all being.

 

115. the next sphere: Of the Fixed Stars.

 

120. to their own causes and effects: Each sphere to those causes and effects influenced by its particular powers.

 

123. takes power from above: From God. and does its work below: Ultimately upon man (the influence of the heavens upon mortal lives) but intermediately some of the work of each sphere must be to transmit certain powers (undiminished) to the spheres below.

 

124-126. Beatrice, as ever, is acting as Dante’s teacher. Here, in a military figure, she instructs him to take careful note of how her argument proceeds through the next point, that by her example Dante may learn how to defend the ford (the crossing to the truth) by himself.

 

127. gyres: Circlings.

 

129. the Blessed Movers: The Angels, Powers, Principalities, and Intelligences who influence each sphere.

 

130. the Heaven made loveliest by many lamps: The Sphere of the Fixed Stars.

 

131-132.