"I have been a wanderer, but I have always found my way back to God."

"The world is a book, and those who do not travel read only one page."

"I was measuring the heavens, now I must measure the shadows of the Earth. Though my soul was from the heavens, the shadow of my body lies here."

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

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