Explore Quotes by Carl Sagan

I've written a number of books that have to do with the evolution of humans, human intelligence, human emotions.

We hunger to understand, so we invent myths about how we imagine the world is constructed - and they're, of course, based upon what we know, which is ourselves and other animals. So we make up stories about how the world was hatched from a cosmic egg or created after the mating of cosmic deities or by some fiat of a powerful being.

We are not without empathetic terror when we open Pascal's 'Pensees' and read, 'I am the great silent spaces between worlds.'

We start out a million years ago in a small community on some grassy plain; we hunt animals, have children, and develop a rich social, sexual, and intellectual life, but we know almost nothing about our surroundings.

There is a wide, yawning black infinity. In every direction, the extension is endless; the sensation of depth is overwhelming. And the darkness is immortal. Where light exists, it is pure, blazing, fierce; but light exists almost nowhere, and the blackness itself is also pure and blazing and fierce.

The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking - it's that credulous and confused thinking can be much more lethal in ways it was never before.

Today, we're still loaded down - and, to some extent, embarrassed - by ancient myths, but we respect them as part of the same impulse that has led to the modern, scientific kind of myth. But we now have the opportunity to discover, for the first time, the way the universe is in fact constructed as opposed to how we would wish it to be constructed.

Most of the people that I deal with are human. So I've had a lot of experience with that.

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?

The boundary between space and the earth is purely arbitrary. And I'll probably always be interested in this planet - it's my favorite.

You probably don't need more weapons than what's required to destroy every city on earth. There's only 2,300 cities. So, the United States, by that criteria, only needs 2,300 nuclear weapons - well, we've got more than 25,000!

Even these stars, which seem so numerous, are as sand, as dust - or less than dust - in the enormity of the space in which there is nothing.

We're in very bad trouble if we don't understand the planet we're trying to save.

It's been said that astronomy is a humbling and, I might add, a character-building experience.

We are the representatives of the cosmos; we are an example of what hydrogen atoms can do, given 15 billion years of cosmic evolution.

No other planet in the solar system is a suitable home for human beings; it's this world or nothing. That's a very powerful perception.

In our obscurity - in all this vastness - there is no hint that help will come from elsewhere to save us from ourselves. It is up to us.

What is called for is an exquisite balance between two conflicting needs: the most skeptical scrutiny of all hypotheses that are served up to us and at the same time a great openness to new ideas. If you are only skeptical, then no new ideas make it through to you. On the other hand, if you are open to the point of gullibility and have not an ounce of skeptical sense in you, then you cannot distinguish useful ideas from the worthless ones.

One glance at a book and you hear the voice of another person, perhaps someone dead for 1,000 years. To read is to voyage through time.

My view is that if there is no evidence for it, then forget about it. An agnostic is somebody who doesn’t believe in something until there is evidence for it, so I’m agnostic.

An extraterrestrial being, newly arrived on Earth - scrutinizing what we mainly present to our children in television, radio, movies, newspapers, magazines, the comics, and many books - might easily conclude that we are intent on teaching them murder, rape, cruelty, superstition, credulity, and consumerism. We keep at it, and through constant repetition many of them finally get it.