Life is a perpetual instruction in cause and effect.

In a library we are surrounded by many hundreds of dear friends, but they are imprisoned by an enchanter in these paper and leathern boxes.

Our first mistake is the belief that the circumstance gives the joy which we give to the circumstance.

Courage consists in equality to the problem before us.

The machine unmakes the man. Now that the machine is so perfect, the engineer is nobody.

The world is always childish, and with each new gewgaw of a revolution or new constitution that it finds, thinks it shall never cry any more.

The sea, washing the equator and the poles, offers its perilous aid, and the power and empire that follow it... ''Beware of me,'' it says, ''but if you can hold me, I am the key to all the lands.