As you lecture, you keep watching the faces, and information keeps coming back to you all the time.

Our business is with life, not death.

Not all living creatures die. An amoeba, for example, need never die; it need not even, like certain generals, fade away. It just divides and becomes two new amoebas.

There is nothing worth having that can he obtained by nuclear war - nothing material or ideological - no tradition that it can defend. It is utterly self-defeating.

The only use for an atomic bomb is to keep somebody else from using one. It can give us no protection - only the doubtful satisfaction of retaliation...

A scientist should be the happiest of men. Not that science isn't serious; but as everyone knows, being serious is one way of being happy, just as being gay is one way of being unhappy.

There's life all over this universe, but the only life in the solar system is on earth, and in the whole universe we are the only men.