I say that the Starry Heaven may be compared to Physics because of three properties, and to Metaphysics because of three others: for it displays to us two visible objects, namely the multitude of stars and the Galaxy [...]; and it discloses one of its poles to us and keeps the other hidden; and it discloses one of its movements to us, from east to west, and keeps the other, which it makes from west to east, almost hidden from us. [...]
I say that the Starry Heaven manifests many stars to us [...] they count 1022 starry bodies [1000+20+2] [...]
For by two we understand local movement [...] By twenty is signified the movement by alteration [...] By a thousand is signified the movement of growth [...] And Physics manifests only these three movements [...]
Because of the Galaxy this heaven has a great resemblance to Metaphysics. Hence [...] the Galaxy is nothing but a multitude of fixed stars [...] so small that we are unable to distinguish them from here below [...] except that we understand these things by their effects, and Metaphysics treats of the primal substances, which we likewise cannot understand except by their effects [...]
Moreover, the pole which we see signifies the sensible things, which [...] Physics treats; and the pole which we do not see signifies the things that are immaterial [...] which Metaphysics treats [...].
Moreover [...] by the movement with which each day it revolves [...] it signifies the corruptible things of nature [...] and these Physics treats. By the almost imperceptible movement which it makes from west to east at the rate of one degree in a hundred years, it signifies the incorruptible things [...] and these Metaphysic..Convivio II, XIV, 1-12