The heaven of Jupiter may be compared to Geometry because of two properties: one is that it moves between two heavens that are antithetical to its fine temperance, namely that of Mars and that of Saturn; [...] the other is that among all the stars it appears white, almost silvery.

And these [two] things are found in the science of Geometry. Geometry moves between two things antithetical to it, namely the point and the circle [...] for the point cannot be measured because of its indivisibility, and it is impossible to square the circle perfectly because of its arc, and so it cannot be measured exactly. Geometry is furthermore most white insofar as it is without taint of error and most certain both in itself and in its handmaid, which is called Optics.

Convivio II, XIII, 25-27