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.

The squares of the periodic times are proportional to the cubes of the mean distances from the sun.

I believe only and alone in the service of Jesus Christ. In him is all refuge and solace.

O telescope, instrument of much knowledge, more precious than any sceptre!

...Those laws are within the grasp of the human mind. God wanted us to recognize them by creating us after his own image so that we could share in his own thoughts... and if piety allow us to say so, our understanding is in this respect of the same kind as the divine, at least as far as we are able to grasp something of it in our mortal life.

Nature uses as little as possible of anything.

If God himself has waited six thousand years for someone to contemplate his works, my book can wait for a hundred.