Thomas Aquinas

One cannot measure the motion of a body perfectly unless the path that it follows is known since magnitude is measured by motion and motion by magnitude, as Aristotle says in IV Physics. Therefore, since the path of motion of the luminaries cannot be known by man for certain, the consequence is that the measure of their motions cannot perfectly be known either, and so he says, "to lead each," i.e., the light and the darkness, "to its limits," by showing the reason for the appearance and disappearance of each of the luminaries as to …

Commentary on Job ↗