For a traveler going from any place toward the north, that pole of the daily rotation gradually climbs higher, while the opposite pole drops down an equal amount.

So far as hypotheses are concerned, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it.

Moreover, since the sun remains stationary, whatever appears as a motion of the sun is really due rather to the motion of the earth.

Mathematics is written for mathematicians.

The massive bulk of the earth does indeed shrink to insignificance in comparison with the size of the heavens.

In the midst of all dwells the sun.

Not only the phenomena of the others followed from this, but also it so bound together both the order and magnitude of all the planets and the spheres and the heaven itself, that in no single part could one thing be altered without confusion among the other parts and in all the universe.