In more than one respect, the exploring of the Solar System and homesteading other worlds constitutes the beginning, much more than the end, of history.

Somewhere, something incredible is waiting to be known.

It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.

Imagination will often carry us to worlds that never were. But without it we go nowhere.

I don't want to believe. I want to know.

The absence of evidence is not the evidence of absence.

The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.

We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology.

For small creatures such as we the vastness is bearable only through love.

You have to know the past to understand the present.

No sign, so far, of anything sinister—but I live in hope.

My friends and I are crazy. That's the only thing that keeps us sane!

Living up to an image that you have of yourself or that other people have of you is inauthentic living.

The desolation and terror of, for the first time, realizing that the mother can lose you, or you her, and your own abysmal loneliness and helplessness without her.

Reading Chaucer is like brushing through the dewy grass at sunrise.

Think of an abstract painting as very, very low relief - a thing, not a picture.

I fast for greater physical and mental efficiency

Each of us has more opportunities to do good and to be good than we ever use.

The future never just happened. It was created.