Carl Sagan

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

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

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. ”

All of the books in the world contain no more information than is broadcast as video in a single large American city in a single year. Not all bits have equal value. ”

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. ”

Science is a way of thinking much more than it is a body of knowledge. ”

When you make the finding yourself - even if you're the last person on Earth to see the light - you'll never forget it. ”

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? ”

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. ”

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. ”