I recently discussed with an intelligent and well-disposed man the threat of another war, which in my opinion would seriously endanger the existence of mankind, and I remarked that only a supranational organization would offer protection from that danger. Thereupon my visitor, very calmly and coolly, said to me: "Why are you so deeply opposed to the disappearance of the human race?".

It should be possible to explain the laws of physics to a barmaid.

Hail to the man who went through life always helping others, knowing no fear, and to whom aggressiveness and resentment are alien. Such is the stuff of which the great moral leaders are made.

The theory must not contradict empirical facts.

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.

We can understand almost anything, but we can't understand how we understand.

The leader is one who, out of the clutter, brings simplicity... out of discord, harmony... and out of difficulty, opportunity.