Science is the process of thinking God's thoughts after Him.

Truth is the daughter of time, and I feel no shame in being her midwife.

I used to measure the Heavens, now I measure the shadows of Earth. The mind belonged to Heaven, the body's shadow lies here.

So, Fabricius, I already have this: that the most true path of the planet [Mars] is an ellipse, which Dürer also calls an oval, or certainly so close to an ellipse that the difference is insensible.

Planets move in ellipses with the Sun at one focus.

It may be well to wait a century for a reader, as God has waited six thousand years for an observer.

As soon as somebody demonstrates the art of flying, settlers from our species of man will not be lacking on the Moon and Jupiter. Who would have believed that a huge ocean could be crossed more peacefully and safely than the the narrow expanse of the Adriatic, the Baltic Sea or the English Channel? Given ships or sails adapted to the breezes of heaven, there will be those who will not shrink from even that vast expanse.