In the midst of all dwells the sun.

For I am not so enamoured of my own opinions that I disregard what others may think of them.

More stars in the north are seen not to set, while in the south certain stars are no longer seen to rise.

In the first book I shall describe all the positions of the spheres, along with the motions which I attribute to the Earth, so that the book will contain as it were the general structure of the universe. In the remaining books I relate the motions of the remaining stars, and all the spheres, to the mobility of the Earth, so that it can be thence established how far the motions and appearances of the remaining stars and spheres can be saved, if they are referred to the motions of the Earth.

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

Every light has its shadow, and every shadow hath a succeeding morning.

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