We find it hard to picture to ourselves the state of mind of a man of older days who firmly believed that the Earth was the centre of the Universe, and that all the heavenly bodies revolved around it. He could feel beneath his feet the writhings of the damned amid the flames; very likely he had seen with his own eyes and smelt with his own nostrils the sulphurous fumes of Hell escaping from some fissure in the rocks. Looking upwards, he beheld ... the incorruptible firmament, wherein the stars hung like so many lamps.

A simple style is like white light. Although complex, it does not appear to be so.

The Arab who built himself a hut with marbles from the temple of Palmyra is more philosophical than all the curators of the museums of London, Paris, and Munich.

What frightens us most in a madman is his sane conversation.

Silence is the wit of fools.

An education which does not cultivate the will is an education that depraves the mind.

Men are not created to know, men are not created to understand ... and our illusions increase with our knowledge.