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

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

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

For it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study.

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

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

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.