Nicolaus Copernicus — "For I have found that the motions of the planets are more regular and orderly if…"

"For the Earth, which is a planet, must therefore move in a circle around the Sun."

"Therefore, we should not be surprised if the earth moves, for it is a planet, and all planets move."

"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."

"For the motions of the planets are so much more orderly and harmonious if they are referred to the sun as the center."

"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…"