Carl Sagan Quotes

402 Sourced Quotes

Every thinking person fears nuclear war and every technological nation plans for it. Everyone knows it's madness, and every country has an excuse.

Carl Sagan
For as long as there been humans we have searched for our place in the cosmos. Where are we? Who are we? We find that we live on an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. This perspective is a courageous continuation of our penchant for constructing and testing mental models of the skies; the Sun as a red-hot stone, the stars as a celestial flame, the Galaxy as the backbone of night.

Carl Sagan
I think people in power have a vested interest to oppose critical thinking.

Carl Sagan
There is a place with four suns in the sky — red, white, blue, and yellow; two of them are so close together that they touch, and star-stuff flows between them. I know of a world with a million moons. I know of a sun the size of the Earth — and made of diamond. There are atomic nuclei a few miles across which rotate thirty times a second. There are tiny grains between the stars, with the size and atomic composition of bacteria. There are stars leaving the Milky Way, and immense gas clouds falling into it. There are turbulent plasmas writhing with X- and gamma-rays and mighty stellar explosions. There are, perhaps, places which are outside our universe. The universe is vast and awesome, and for the first time we are becoming a part of it.

Carl Sagan
What distinguishes our species is thought. The cerebral cortex is in a way a liberation. We need no longer be trapped in the genetically inherited behavior patterns of lizards and baboons: territoriality and aggression and dominance hierarchies. We are each of us largely responsible for what gets put in to our brains. For what as adults we wind up caring for and knowing about. No longer at the mercy of the reptile brain we can change ourselves. Think of the possibilities.

Carl Sagan
Curiosity and the urge to solve problems are the emotional hallmarks of our species...

Carl Sagan
The very act of understanding is a celebration of joining, merging, even if on a very modest scale, with the magnificence of the Cosmos.

Carl Sagan
Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder.

Carl Sagan
Many of the dangers we face indeed arise from science and technology — but, more fundamentally, because we have become powerful without becoming commensurately wise. The world-altering powers that technology has delivered into our hands now require a degree of consideration and foresight that has never before been asked of us.

Carl Sagan
The fact that so little of the findings of modern science is prefigured in Scripture to my mind casts further doubt on it divine inspiration.

Carl Sagan
Black holes may be apertures to elsewhen. Were we to plunge down a black hole, we would re-emerge, it is conjectured, in a different part of the universe and in another epoch of time.... Black holes may be the entrances to Wonderland. But are there Alices or white rabbits?

Carl Sagan
The price we pay for anticipation of the future is anxiety about it

Carl Sagan
It is too late to be shy and hesitant. We have announced our presence to the cosmos — in a backward and groping and unrepresentative manner, to be sure — but here we are!

Carl Sagan
The impediment to scientific thinking is not, I think, the difficulty of the subject. Complex intellectual feats have been mainstays even of oppressed cultures. Shamans, magicians and theologians are highly skilled in their intricate and arcane arts. No, the impediment is political and hierarchical.

Carl Sagan
The pattern of evolutionary causality is a web of astonishing complexity; the incompleteness of our understanding humbles us.

Carl Sagan
It's sometimes easier to reject strong evidence than to admit that we've been wrong, this is information about ourselves worth having.

Carl Sagan
The Bill of Rights decoupled religion from the state, in part because so many religions were steeped in an absolutist frame of mind - each convinced that it alone had a monopoly on the truth and therefore eager for the state to impose this truth on others.

Carl Sagan
Societies will, of course, wish to exercise prudence in deciding which technologies that is, which applications of science are to be pursued and which not. But without funding basic research, without supporting the acquisition of knowledge for its own sake, our options become dangerously limited.

Carl Sagan
The assumption that technical civilizations must necessarily make an appearance, even after many billions of years of biological evolution, implies that the ultimate purpose, or goal, in the formation of stars and planets is the production of intelligent beings and technical civilizations - an idealistic and teleological view.

Carl Sagan
It is a supreme challenge for the popularizer of science to make clear the actual, tortuous history of its great discoveries and the misapprehensions and occasional stubborn refusal by its practitioners to change course.

Carl Sagan
The Apollo pictures of the whole Earth conveyed to multitudes something well known to astronomers: On the scale of the worlds - to say nothing of stars or galaxies - humans are inconsequential, a thin film of life on an obscure and solitary lump of rock and metal

Carl Sagan
Each of us is a tiny being, permitted to ride on the outermost skin of one of the smaller planets for a few dozen trips around the local star.

Carl Sagan
I find science so much more fascinating than science fiction. It also has the advantage of being true.

Carl Sagan
We seem, these days, much more willing to recognize the perils before us than we were even a decade ago. The newly recognized dangers threaten all of us, equally. No one can say how it will turn out down here. But this is also, we may note, the first time that a species has become able to journey to the planets and the stars. Sailors on a becalmed sea, we sense a stirring of the breeze.

Carl Sagan
Science — pure science, science not for any practical application but for its own sake — is a deeply emotional matter for those who practice it, as well as for those nonscientists who every now and then dip in to see what's been discovered lately.

Carl Sagan
We are constantly prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs.

Carl Sagan
The asteroid belt may be a place where a planet was once prevented from forming because of the gravitational tides of the giant nearby planet Jupiter; or it may be the shattered remains of a planet that blew itself up. This seems improbable because no scientist on Earth knows how a planet might blow itself up, which is probably just as well.

Carl Sagan
The so-called generation gap is a consequence of the rate of social and technological change. Even within a human lifetime, the change is so great that many people are alienated from their own society. Margaret Mead had described older people as involuntary immigrants from the past to the present.

Carl Sagan
In the deepest sense the search for extraterrestrial intelligence is a search for ourselves.

Carl Sagan
Quantify. If whatever it is you're explaining has some measure, some numerical quantity attached to it, you'll be much better able to discriminate among competing hypotheses. What is vague and qualitative is open to many explanations.

Carl Sagan