"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. Although my mind was heaven-bound, the shadow of m…"

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

"My goal is to show that the heavenly machine is not a kind of divine living being but similar to a clockwork insofar …"

"Nature uses as little as possible of anything."

"The die is cast; I have written my book; it will be read either in the present age or by posterity, it matters not wh…"

"We do not ask for what useful purpose the birds do sing, for song is their pleasure since they were created for singi…"

"In Terra inest virtus, quae Lunam del."

"There is a force in the earth which causes the moon to move."

"The earth is the sphere, the measure of all; round it describe a dodecahedron; the sphere including this will be Mars…"