"I believe that in the long run, the only way we can survive is to make the world safe for peace."

"We must be prepared to make the effort to understand the world, and to live in it as human beings."

"It is perfectly obvious that the whole world is going to hell. The only possible chance that it might not is that we do not attempt to prevent it from doing so."

"In the spring of 1929, I returned to the United States. I was homesick for this country. I had learned in my student days a great deal about the new physics. I wanted to pursue this myself, to explain…"

"The greatest discovery is to find oneself."