We regard it as a certainty that the earth, enclosed between poles, is bounded by a spherical surface.

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.

To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.

The Universe, wrought for us by a supremely good and orderly Creator.

Among the authorities it is generally agreed that the Earth is at rest in the middle of the universe, and they regard it as inconceivable and even ridiculous to hold the opposite opinion. However, if we consider it more closely the question will be seen to be still unsettled, and so decidedly not to be despised. For every apparent change in respect of position is due to motion of the object observed, or of the observer, or indeed to an unequal change of both.

Those things which I am saying now may be obscure, yet they will be made clearer in their proper place.

For what could be more beautiful than the heavens which contain all beautiful things.