Science goes from question to question; big questions, and little, tentative answers. The questions as they age grow ever broader, the answers are seen to be more limited.

When you have no experience of pain, it is rather hard to experience joy.

We've committed many war crimes in Vietnam - but I'll tell you something interesting about that. We were committing war crimes in World War II, before the Nuremberg trials were held and the principle of war crimes was stated.

I am growing old, and my future, so to speak, is already behind me.

The great questions are those an intelligent child asks and, getting no answers, stops asking.

[Attributing the origin of life to spontaneous generation.] However improbable we regard this event, it will almost certainly happen at least once.... The time... is of the order of two billion years.... Given so much time, the "impossible" becomes possible, the possible probable, and the probable virtually certain. One only has to wait: time itself performs the miracles.

I think I know what is bothering the students. I think that what we are up against is a generation that is by no means sure that it has a future.