Therefore I would not have it unknown to Your Holiness, the the only thing which induced me to look for another way of reckoning the movements of the heavenly bodies was that I knew that mathematicians by no means agree in their investigation thereof.

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

In so many and such important ways, then, do the planets bear witness to the earth's mobility.

Although all the good arts serve to draw man's mind away from vices and lead it toward better things, this function can be more fully performed by this art, which also provides extraordinary intellectual pleasure.

The earth together with its surrounding waters must in fact have such a shape as its shadow reveals, for it eclipses the moon with the arc of a perfect circle.

Of all things visible, the highest is the heaven of the fixed stars.

Astronomy is written for astronomers