"I have been a mortal, and I have faced my own mortality with courage."

"I much prefer the sharpest criticism of a single intelligent man to the thoughtless approval of the masses."

"The diversity of the phenomena of nature is so great, and the treasures hidden in the heavens so rich, precisely in order that the human mind shall never be lacking in fresh nourishment."

"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…"

"I have discovered the harmony of the spheres."