"I have often been poor, but I have always been rich in spirit."

"I would rather be a good Christian than a good astronomer."

"My goal is to show that the heavenly machine is not a kind of divine living being but similar to a clockwork insofar as all the manifold motions are taken care of by one single absolutely simple magne…"

"The Earth has a soul, and it is sick with melancholy."

"Provide ship or sails adapted to the heavenly breezes, and there will be some who will not fear even that void [of space]… . So, for those who will come shortly to attempt this journey, let us establi…"