99+ Best Carl Sagan Quotes: Exclusive Selection

Carl Edward Sagan was an American astronomer, cosmologist, astrophysicist, astrobiologist, author, science popularizer, and science communicator in astronomy and other natural sciences. Profoundly inspirational Carl Sagan quotes will challenge the way you think, change the way you live and transform your whole life.

Famous Carl Sagan Quotes

One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back. – Carl Sagan

Ask courageous questions. Do not be satisfied with superficial answers. Be open to wonder and at the same time subject all claims to knowledge, without exception, to intense skeptical scrutiny. Be aware of human fallibility. Cherish your species and your planet. – Carl Sagan

The illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world. – Carl Sagan

Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage – at the very least the courage to question the conventional wisdom. – Carl Sagan

The beauty of a living thing is not the atoms that go into it, but the way those atoms are put together. – Carl Sagan

The well-meaning contention that all ideas have equal merit seems to me little different from the disastrous contention that no ideas have any merit. – Carl Sagan

History is full of people who out of fear, or ignorance, or lust for power has destroyed knowledge of immeasurable value which truly belongs to us all. We must not let it happen again. – Carl Sagan

The absence of evidence is not the evidence of absence. – Carl Sagan

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

How is it that hardly any major religion has looked at science and concluded, this is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant? – 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

Where did God come from? If we decide this is an unanswerable question, why not save a step and conclude that the origin of the universe is an unanswerable question. – Carl Sagan

We are like butterflies who flutter for a day and think it is forever. – Carl Sagan

Finding the occasional straw of truth awash in a great ocean of confusion and bamboozle requires intelligence, vigilance, dedication, and courage. But if we don’t practice these tough habits of thought, we cannot hope to solve the truly serious problems that face us — and we risk becoming a nation of suckers, up for grabs by the next charlatan who comes along. – Carl Sagan

Somewhere, something incredible is waiting to be known. – Carl Sagan

Not all birds can fly. What separates the flyers from the walkers is the ability to take off. – Carl Sagan

All civilizations become either spacefaring or extinct. – Carl Sagan

Who are we, if not measured by our impact on others? That’s who we are! We’re not who we say we are, we’re not who we want to be – we are the sum of the influence and impact that we have, in our lives, on others. – Carl Sagan

And you are made of a hundred trillion cells. We are, each of us, a multitude. – Carl Sagan

We live on a mote of dust suspended in a sunbeam. – Carl Sagan

At the heart of science is an essential balance between two seemingly contradictory attitudes-an openness to new ideas, no matter how bizarre or counterintuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. – Carl Sagan

If you look at Earth from space you see a dot, that’s here. That’s home. That’s us. It underscores the responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we’ve ever known. – Carl Sagan

For all our conceits about being the center of the universe, we live in a routine planet of a humdrum star stuck away in an obscure corner … on an unexceptional galaxy which is one of about 100 billion galaxies. … That is the fundamental fact of the universe we inhabit, and it is very good for us to understand that. – Carl Sagan

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

The universe seems neither benign nor hostile, merely indifferent. – Carl Sagan

Nothing disturbs me more than the glorification of stupidity. – Carl Sagan

Even Johannes Kepler, Isaac Newton, Charles Darwin, Gregor Mendel, and Albert Einstein made serious mistakes. But the scientific enterprise arranges things so that teamwork prevails: What one of us, even the most brilliant among us, misses, another of us, even someone much less celebrated and capable, may detect and rectify. – Carl Sagan

What a marvelous cooperative arrangement – plants and animals each inhaling each other’s exhalations, a kind of planet-wide mutual mouth-to-stoma resuscitation, the entire elegant cycle powered by a star 150 million kilometers away. – Carl Sagan

Anything else you’re interested in is not going to happen if you can’t breathe the air and drink the water. Don’t sit this one out. Do something. You are by accident of fate alive at an absolutely critical moment in the history of our planet. – Carl Sagan

There are many hypotheses in science which are wrong. That’s perfectly all right: it’s the aperture to finding out what’s right. Science is a self-correcting process. – Carl Sagan

Science is an attempt, largely successful, to understand the world, to get a grip on things, to get hold of ourselves, to steer a safe course. Microbiology and meteorology now explain what only a few centuries ago was considered sufficient cause to burn women to death. – Carl Sagan

We live on a hunk of rock and metal that circles a humdrum star that is one of 400 billion other stars that make up the Milky Way Galaxy which is one of billions of other galaxies which make up a universe which may be one of a very large number, perhaps an infinite number, of other universes. That is a perspective on human life and our culture that is well worth pondering. – Carl Sagan

We were wanderers from the beginning. – 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

Understanding is a kind of ecstasy. – Carl Sagan

It’s hard to kill a creature once it lets you see its consciousness. – Carl Sagan

Nevertheless, (Jefferson) believed that the habit of skepticism is an essential prerequisite for responsible citizenship. He argued that the cost of education is trivial compared to the cost of ignorance, of leaving government to the wolves. He taught that the country is safe only when the people rule. – Carl Sagan

We are made of stellar ash. Our origin and evolution have been tied to distant cosmic events. The exploration of the cosmos is a voyage of self-discovery. – Carl Sagan

We are star stuff harvesting sunlight. – Carl Sagan

A still more glorious dawn awaits / not a sunrise, but a galaxy-rise / a morning filled with 400 billion suns / the rising of the milky way – Carl Sagan

We are the product of 4.5 billion years of fortuitous, slow biological evolution. There is no reason to think that the evolutionary process has stopped. Man is a transitional animal. He is not the climax of creation. – Carl Sagan

The values of science and the values of democracy are concordant, in many cases indistinguishable. Science and democracy began – in their civilized incarnations – in the same time and place, Greece in the seventh and sixth centuries B.C. . . . Science thrives on, indeed requires, the free exchange of ideas; its values are antithetical to secrecy. Science holds to no special vantage points or privileged positions. Both science and democracy encourage unconventional opinions and vigorous debate. Both demand adequate reason, coherent argument, rigorous standards of evidence and honesty. – Carl Sagan

We are, each of us, a multitude. Within us is a little universe. – Carl Sagan

We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster. We might get away with it for a while, but sooner or later this combustible mixture of ignorance and power is going to blow up in our faces. – Carl Sagan

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

We live in a vast and awesome universe in which, daily, suns are made, and worlds destroyed, where humanity clings to an obscure clod of rock. – Carl Sagan

National boundaries are not evident when we view the Earth from space. Fanatical ethnic or religious or national chauvinisms are a little difficult to maintain when we see our planet as a fragile blue crescent fading to become an inconspicuous point of light against the bastion and citadel of the stars. – Carl Sagan

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

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

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. – Carl Sagan

Every cell is a triumph of natural selection, and we’re made of trillions of cells. Within us, is a little universe. – Carl Sagan

If chimpanzees have consciousness, if they are capable of abstractions, do they not have what until now has been described as ‘human rights’? How smart does a chimp have to be before killing him constitutes murder? – Carl Sagan

Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense. – Carl Sagan

The significance of our lives and our fragile planet is then determined only by our own wisdom and courage. We are the custodians of life’s meaning. We long for a Parent to care for us, to forgive us our errors, to save us from our childish mistakes. But knowledge is preferable to ignorance. Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal. – Carl Sagan

Science is not perfect. It’s often misused; it’s only a tool, but it’s the best tool we have. Self-correcting , ever changing, applicable to everything: with this tool, we vanquish the impossible. – Carl Sagan

I don’t want to believe. I want to know. – Carl Sagan

Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history. – Carl Sagan

But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown. – Carl Sagan

Stars are phoenixes, rising from their own ashes. – Carl Sagan

All of us cherish our beliefs. They are, to a degree, self-defining. When someone comes along who challenges our belief system as insufficiently well-based – or who, like Socrates, merely asks embarrassing questions that we haven’t thought of, or demonstrates that we’ve swept key underlying assumptions under the rug – it becomes much more than a search for knowledge. It feels like a personal assault. – Carl Sagan

Better the hard truth, I say, than the comforting fantasy. – Carl Sagan

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. – Carl Sagan

The cure for a fallacious argument is a better argument, not the suppression of ideas. – Carl Sagan

For me, the most ironic token of [the first human moon landing] is the plaque signed by President Richard M. Nixon that Apollo 11 took to the moon. It reads, ‘We came in peace for all Mankind.’ As the United States was dropping seven and a half megatons of conventional explosives on small nations in Southeast Asia, we congratulated ourselves on our humanity. We would harm no one on a lifeless rock. – Carl Sagan

If we continue to accumulate only power and not wisdom, we will surely destroy ourselves. – Carl Sagan

The difference between physics and metaphysics is not that the practitioners of one are smarter than the practitioners of the other. The difference is that the metaphysicist has no laboratory. – Carl Sagan

Where we have strong emotions, we’re liable to fool ourselves. – Carl Sagan

There are no forbidden questions in science, no matters too sensitive or delicate to be probed, no sacred truths. – Carl Sagan

We can judge our progress by the courage of our questions and the depth of our answers, our willingness to embrace what is true rather than what feels good. – Carl Sagan

It took the Church until 1832 to remove Galileo ‘s work from its list of books which Catholics were forbidden to read at the risk of dire punishment of their immortal souls. – Carl Sagan

It is the responsibility of scientists never to suppress knowledge, no matter how awkward that knowledge is, no matter how it may bother those in power; we are not smart enough to decide which pieces of knowledge are permissible, and which are not. – Carl Sagan

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. – Carl Sagan

If God is omnipotent and omniscient, why didn’t he start the universe out in the first place so it would come out the way he wants? Why’s he constantly repairing and complaining? No, there’s one thing the Bible makes clear: The biblical God is a sloppy manufacturer. He’s not good at design, he’s not good at execution. He’d be out of business, if there was any competition. – Carl Sagan

Think of how many religions attempt to validate themselves with prophecy. Think of how many people rely on these prophecies, however vague, however unfulfilled, to support or prop up their beliefs. Yet has there ever been a religion with the prophetic accuracy and reliability of science? … No other human institution comes close. – Carl Sagan

It’s a lazy Saturday afternoon, there’s a couple lying naked in bed reading Encyclopediea Brittannica to each other, and arguing about whether the Andromeda Galaxy is more ‘numinous’ than the Ressurection. Do they know how to have a good time, or don’t they? – Carl Sagan

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what’s true. – Carl Sagan

We should be teaching our children the scientific method and the reasons for a Bill of Rights. With it comes a certain decency, humility and community spirit. – Carl Sagan

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

If I finish a book a week, I will read only a few thousand books in my lifetime, about a tenth of a percent of the contents of the greatest libraries of our time. The trick is to know which books to read. – Carl Sagan

An organism at war with itself is doomed. – Carl Sagan

If we can’t think for ourselves, if we’re unwilling to question authority, then we’re just putty in the hands of those in power. But if the citizens are educated and form their own opinions, then those in power work for us. In every country, we should be teaching our children the scientific method and the reasons for a Bill of Rights. With it comes a certain decency, humility and community spirit. In the demon-haunted world that we inhabit by virtue of being human, this may be all that stands between us and the enveloping darkness. – Carl Sagan

There is a reward structure in science that is very interesting: Our highest honors go to those who disprove the findings of the most revered among us. So Einstein is revered not just because he made so many fundamental contributions to science, but because he found an imperfection in the fundamental contribution of Isaac Newton. – Carl Sagan

Be grateful everyday for the brief but magnificent opportunity that life provides. – Carl Sagan

In science it often happens that scientists say, ‘You know that’s a really good argument; my position is mistaken,’ and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn’t happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. – Carl Sagan

In many cultures it is customary to answer that God created the universe out of nothing. But this is mere temporizing. If we wish courageously to pursue the question, we must, of course ask next where God comes from? And if we decide this to be unanswerable, why not save a step and conclude that the universe has always existed? – Carl Sagan

We humans look rather different from a tree. Without a doubt we perceive the world differently than a tree does. But down deep, at the molecular heart of life, the trees and we are essentially identical. – Carl Sagan

When you realize that no one really knows what they are doing and that everyone is doing the best they can according to their own level of consciousness, life gets a lot easier. Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense. – Carl Sagan

We on Earth have just awakened to the great oceans of space and time from which we have emerged. We are the legacy of 15 billion years of cosmic evolution. We have a choice: We can enhance life and come to know the universe that made us, or we can squander our 15 billion-year heritage in meaningless self-destruction. What happens in the first second of the next cosmic year depends on what we do, here and now, with our intelligence and our knowledge of the cosmos. – Carl Sagan

But nature is always more subtle, more intricate, more elegant than what we are able to imagine. – Carl Sagan

Better by far to embrace the hard truth than a reassuring fable. If we crave some cosmic purpose, then let us find ourselves a worthy goal. – Carl Sagan

Extinction is the rule. Survival is the exception. – Carl Sagan

I also wish that the Pledge of Allegiance were directed at the Constitution and the Bill of Rights, as it is when the President takes his oath of office, rather than to the flag and the nation – Carl Sagan

Don’t judge everyone else by your own limited experience. – Carl Sagan

Demon mean knowledge in Greek, especially about the material world. Science means knowledge in Latin. A jurisdictional dispute is exposed, even if we look no further – Carl Sagan

The cosmic calendar compresses the local history of the universe into a single year. If the universe began on January 1st it was not until May that the Milky Way formed. Other planetary systems may have appeared in June, July and August, but our Sun and Earth not until mid-September. Life arose soon after. We humans appear on the cosmic calendar so recently that our recorded history occupies only the last few seconds of the last minute of December 31st. – Carl Sagan

Even through your hardest days, remember we are all made of stardust. – Carl Sagan

The neurochemistry of the brain is astonishingly busy, the circuitry of a machine more wonderful than any devised by humans. But there is no evidence that its functioning is due to anything more than the 10(14) neural connections that build an elegant architecture of consciousness. – Carl Sagan

Religions contradict one another-on small matters, such as whether we should put on a hat or take one off on entering a house of worship, or whether we should eat beef and eschew pork or the other way around, all the way to the most central issues, such as whether there are no gods, one God, or many gods. – Carl Sagan

It is clear that the nations of the world now can only rise and fall together. It is not a question of one nation winning at the expense of another. We must all help one another, or all perish together. – Carl Sagan

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