At rest, however, in the middle of everything is the sun.

Those who know that the consensus of many centuries has sanctioned the conception that the earth remains at rest in the middle of the heavens as its center, would, I reflected, regard it as an insane pronouncement if I made the opposite assertion that the earth moves.

Finally we shall place the Sun himself at the center of the Universe.

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

First of all, we must note that the universe is spherical.

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