"The universe is a machine, and God is its engineer."

"I have often tried to grasp that which I have found."

"See, I cast the die, and I write the book. Whether it is to be read by the people of the present or of the future makes no difference: let it await its reader for a hundred years, if God himself has s…"

"I also ask you my friends not to condemn me entirely to the mill of mathematical calculations, and allow me time for philosophical speculations, my only pleasures."

"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…"