NICHOLAS COPERNICUS

...be assigned original: "deputetur" — referring back to the motion of the observer discussed on the previous page., that same motion will appear in everything which is outside of it, but in the opposite direction, as if the objects were passing by. Such is, in the first place, the daily revolution. For this appears to sweep along the entire universe, except for the Earth and those things around it. But if you were to grant that the heavens have nothing of this motion, but that the Earth instead revolves from the west to the east—and if you consider this seriously regarding the apparent rising and setting of the Sun, Moon, and Stars—you will find that this is indeed the case. Since it is the heavens which contain and cover all things, the common "place" of the entire universe, it is not immediately clear why motion should not be attributed to the thing contained rather than to the container, or to the thing located rather than to the thing providing the location.

Indeed, the Pythagoreans Heraclides and Ecphantus, as well as Nicetas of Syracuse (as mentioned in Cicero), were of this opinion, depicting the Earth as revolving in the center of the universe. For they believed that the stars set because the Earth's bulk stands in the way, and they rise when the Earth moves aside. If we assume this, another no less important doubt follows concerning the position of the Earth, although almost everyone has now accepted and believed that the Earth is the center of the world.

For if someone were to deny that the Earth occupies the middle or center of the world, but yet does not admit that the distance is so great as to be comparable to the sphere of the fixed starsStars that appear to stay in fixed patterns (constellations) relative to one another, unlike "wandering" planets., but is nevertheless notable and evident in relation to the orbits of the Sun and other stars—and if he thinks that their motion appears diverse for that reason, as if they were regulated by a different center than the center of the Earth—he might perhaps be able to provide a sound explanation for the apparent diverse motion. For the fact that the wandering stars original: "errantia sidera" — the planets. are seen closer to the Earth at some times and farther away at others, necessarily proves that the center of the Earth is not the center of those circular orbits. Thus, it is not even certain whether the Earth draws near to them and moves away, or they to the Earth.

It would not be so surprising if someone, besides that daily revolution, were to imagine another motion for the Earth. Indeed, that the Earth revolves and even wanders with several motions, and is "one of the stars," is a view Philolaus the Pythagorean is said to have held—a mathematician of no ordinary sort, for whose sake Plato did not hesitate to travel to Italy, as those who have written the life of Plato relate.

However, many have thought it can be demonstrated by geometric reasoning that the Earth is in the center of the world; that it is like a point compared to the immensity of the heavens, occupying the place of a center; and for that reason, it is immobile, because when the universe moves, the center...