"I have been a solitary man, but I have found joy in my work."

"I have been tormented by the desire to understand the celestial motions."

"So long as the mother, Ignorance, lives, it is not safe for Science, the offspring, to divulge the hidden causes of things."

"The heavenly motions are nothing but a continuous song for several voices, perceived not by the ear but by the intellect."

"The Earth too wants to have a soul, and the sky wants to rule over it."