We have fallen in love with the body. That's that thing that looks back at us from the mirror. That's the repository of that lovely identity that you keep chasing all your life.

I tell my students, with a feeling of pride that I hope they will share, that the carbon, nitrogen, and oxygen that make up ninety-nine per cent of our living substance were cooked in the deep interiors of earlier generations of dying stars. Gathered up from the ends of the universe, over billions of years, eventually they came to form, in part, the substance of our sun, its planets, and ourselves. Three billion years ago, life arose upon the earth. It is the only life in the solar system.

I think if a physician wrote on a death certificate that old age was the cause of death, he'd be thrown out of the union. There is always some final event, some failure of an organ, some last attack of pneumonia, that finishes off a life. No one dies of old age.

I can conceive of no nightmare so terrifying as establishing communication with a so-called superior (or, if you wish, advanced) technology in outer space.

The concept of war crimes is an American invention.

A scientist should be the happiest of men.

A scientist is in a sense a learned small boy. There is something of the scientist in every small boy. Others must outgrow it. Scientists can stay that way all their lives.