The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it.

It is easier to denature plutonium than to denature the evil spirit of man.

Is it not better for a man to die for a cause in which he believes, such as peace, than to suffer for a cause in which he does not believe, such as war?

What separates me from most so-called atheists is a feeling of utter humility toward the unattainable secrets of the harmony of the cosmos.

If my theory of relativity is proven successful, Germany will claim me as a German and France will declare me a citizen of the world. Should my theory prove untrue, France will say that I am a German, and Germany will declare that I am a Jew.

Common sense is that layer of prejudices which we acquire before we are sixteen.

For scientific endeavor is a natural whole the parts of which mutually support one another in a way which, to be sure, no one can anticipate.