"In the spring of 1936, I was introduced by friends to Jean Tatlock. In the autumn, I began to court her. We were at least twice close enough to marriage to think of ourselves as engaged."

"We have to live with the fact that we have unleashed a terrible force."

"It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them."

"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…"

"It is a problem of how to live with the atomic bomb, and not how to live without it."