Life isn't worth living, unless it is lived for someone else.

Do you believe in miracles? Well, you should. In fact, life itself is a big miracle. There are so many things that are beyond our understanding. There are two ways to live: you can live as if nothing is a miracle; you can live as if everything is a miracle.

There are two different conceptions about the nature of the universe: (1) the world as a unity dependent on humanity; (2) the world as a reality independent of the human factor.

How can he possibly be humble? He hasn't done anything yet.

The creative scientist studies nature with the rapt gaze of the lover, and is guided as often by aesthetics as by rational considerations in guessing how nature works.

My pacifism is not based on any intellectual theory but on a deep antipathy to every form of cruelty and hatred.

If you can't explain what you are doing to a nine-year-old, then either you still don't understand it very well, or it's not all that worthwile in the first place.