Nicolaus Copernicus

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

Nor do I doubt that learned and skillful mathematicians will agree with me if they are willing to give not superficial but profound attention to the arguments I adduce in this work.

Perhaps there will be babblers who, although completely ignorant of mathematics, nevertheless dare to pass judgment on these things, and because of some passage in Holy Scripture, want to distort my book from their purpose.

For the universe, wrought for us by the best and most orderly Workman of all, is a wonderful work.

Having thus assumed the motions which I ascribe to the earth, I have, after long and careful investigation, finally discovered that, if the motions of the other planets be related to the revolution of the earth, and be calculated to the same period, not only do the phenomena of these motions follow therefrom, but also the order and magnitudes of all the planets and spheres, and the heaven itself, are so bound together that in no portion of it can anything be moved without disrupting the order of all the other parts and of the whole universe.

The sphere is the most perfect of all figures, hence it is the form of the world.

Therefore, since it is the heavens that contain all things, it is not the heavens that move, but rather the earth, which is contained within the heavens, that moves.

For the mind, which is created in the image of God, is capable of understanding the divine order of the universe.

In the midst of all dwells the Sun. For who indeed could place this lamp of a better position in this most beautiful temple, than that from which it can at once illuminate all?

I consider the planets themselves to be divine, living creatures.

It is not incredible that the earth moves, but that it stands still, that is incredible.

We are thus brought to a standstill by the realization that our previous theories were not only complicated but also inconsistent.

For it is far better to grasp the mind of God as it is, than to impose our own limited understanding upon it.

The order of the planets is this: Saturn, Jupiter, Mars, Earth, Venus, Mercury.

First of all, the world is spherical. This is because the sphere is the most perfect figure of all, and it is the form of the world.

The Sun, as if seated on a royal throne, governs the family of stars which wheel around it.

I am aware that I have made myself liable to be laughed at by those who consider it an absurdity to suppose that the earth moves.

For it is the work of a good mathematician to compute the motions of the heavenly bodies, and to predict their positions at any given time.

The difficulty of the task, and the novelty of the opinion, almost deterred me from publishing the work.

For the motion of the earth is of such a nature that it can account for all the apparent motions of the heavenly bodies.