"The power of gravity is of such a nature as to penetrate to the very centres of the sun and planets, without suffering the least diminution of its force."

"Tact is the art of making a point without making an enemy."

"The way to chastity is not to struggle directly with incontinent thoughts but to avert the thoughts by some employment, or by reading, or by meditating on other things."

"As a blind man has no idea of colours, so have we no idea of the manner by which the all-wise God perceives and understands all things."

"Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion."