Carl Sagan

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

The professed function of the nuclear weapons on each side is to prevent the other side from using their nuclear weapons. If that's all it is, then we've gotta as: how many nuclear weapons do you need to do that?

I would love to believe that when I die I will live again, that some thinking, feeling, remembering part of me will continue. But as much as I want to believe that, and despite the ancient and worldwide cultural traditions that assert an afterlife, I know of nothing to suggest that it is more than wishful thinking.

It is of interest to note that while some dolphins are reported to have learned English - up to fifty words used in correct context - no human being has been reported to have learned dolphinese.

we make our world significant by the courage of our questions and the depth of our answers

On the day that we do discover that we are not alone, our society may begin to evolve and transform in some incredible and wondrous new ways.

Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs — in time, in space, and in potential — the tidy anthropocentric proscenium of our ancestors.

The cosmos is within us. We are made of star stuff

Writing is perhaps the greatest of human inventions.

We are made of star-stuff. Our bodies are made of star-stuff. There are pieces of star within us all.

The beauty of a living thing is not the atoms that go into it, but the way those atoms are put together. Information distilled over 4 billion years of biological evolution. Incidentally, all the organisms on the Earth are made essentially of that stuff. An eyedropper full of that liquid could be used to make a caterpillar or a petunia if only we knew how to put the components together.

We are, in the most profound sense, children of the Cosmos.

Don't judge everyone else by your own limited experience.

Man is a transitional animal. He is not the climax of creation

The chief deficiency I see in the skeptical movement is its polarization: Us vs. Them - the sense that we have a monopoly on the truth; that those other people who believe in all these stupid doctrines are morons; that if you're sensible, you'll listen to us; and if not, to hell with you. This is nonconstructive. It does not get our message across. It condemns us to permanent minority status.

Human beings grew up in forests; we have a natural affinity for them. How lovely a tree is, straining toward the sky.

Scientists make mistakes. Accordingly, it is the job of the scientist to recognize our weakness, to examine the widest range of opinions, to be ruthlessly self-critical. Science is a collective enterprise with the error-correction machinery often running smoothly.

It does no harm to the romance of the sunset to know a little bit about it.

There are in fact 100 billion galaxies, each of which contain something like a 100 billion stars. Think of how many stars, and planets, and kinds of life there may be in this vast and awesome universe.

Personally, I would be delighted if there were a life after death, especially if it permitted me to continue to learn about this world and others, if it gave me a chance to discover how history turns out.

Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.