All the fifty years of conscious brooding have brought me no closer to answer the question, "What are light quanta?" Of course today every rascal thinks he knows the answer, but he is deluding himself.

If the workers of this world, men and women, decide not to manufacture and transport ammunition, it would end war for all time. We must do that. Dedicate our lives to drying up the source of war; ammunition factories.

I believe the most important mission of the state is to protect the individual and make it possible for him to develop into a creative personality.

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 cannot resolve the problems of the world by unsing the same techniques that have created them.

Watch the stars, and from them learn.

Nobody knows how the stand of our knowledge about the atom would be without him. Personally, [Niels] Bohr is one of the amiable colleagues I have met. He utters his opinions like one perpetually groping and never like one who believes himself to be in possession of the truth.