[O]nly if every individual strives for truth can humanity attain a happier future; the atavisms in each of us that stand in the way of a friendlier destiny can only thus be rendered ineffective.

Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world.

The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. He to whom the realm of the spirit for your own personal joy and to the profit of the community to which your later work belongs.

Imagination is more important than knowledge.

Live life to the fullest. You have to color outside the lines once in a while if you want to make your life a masterpiece. Laugh some every day. Keep growing, keep dreaming, keep following your heart. The important thing is not to stop questioning.

What I see in Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of humility. This is a genuinely religious feeling that has nothing to do with mysticism.

The importance of a problem should not be judged by the number of pages devoted to it.