An evening everyone agrees, is a lost evening.

There are two ways to live: you can live as if nothing is a miracle; you can live as if everything is a miracle. The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt is awe, is as good as dead: his eyes are closed.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.

Persistence is the most powerful force on earth, it can move mountains.

It is nothing short of a miracle that modern methods of teaching have not yet entirely strangled that sacred spirit of curiosity and inquiry, for this delicate plant needs freedom no less than stimulation.

If A is a success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut

Condemnation before investigation is the highest form of ignorance.