has motions serving its overall motions, belonging to bodies that serve its body as a whole, like servants attending to a single servant—he also knows with certainty that each planet’s retinue has its own commander, appointed by the first commander to watch over them. This resembles the organization of armies: they are divided into units, each under a single commander, and these commanders, known as unit leaders, answer to one commander, the commander of the army.

The same applies to the motions of the heavenly bodies recognized by the ancients. These motions—numbering more than forty—all come under seven commanders; and the seven—or eight, since the ancients differed over the number of motions—answer to the first commander.

This knowledge is attained in this way, whether or not a person knows how He first created these bodies—I mean the heavenly bodies—and whether he knows how the existence of all the other