Carl Sagan

They (i. e., the Pythagoreans) did not advocate the free confrontation of conflicting points of view. Instead, like all orthodox religions, they practised a rigidity that prevented them from correcting their errors.

— Carl Sagan

The Platonists and their Christian successors held the peculiar notion that the Earth was tainted and somehow nasty, while the heavens were perfect and divine. The fundamental idea that the Earth is a planet, that we are citizens of the Universe, was rejected and forgotten.

— Carl Sagan

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

— Carl Sagan

If we long for our planet to be important, there is something we can do about it. We make our world significant by the courage of our questions and by the depth of our answers.

— Carl Sagan

We embarked on our journey to the stars with a question first framed in the childhood of our species and in each generation asked anew with undiminished wonder: What are the stars? Exploration is in our nature. We began as wanderers, and we are wanderers still. We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars.

— Carl Sagan

Astronomically, the U. S. S. R. and the United States are the same place.

— Carl Sagan

Relativity does set limits on what humans can ultimately do. But the universe is not required to be in perfect harmony with human aspirations.

— Carl Sagan

I have...a terrible need...shall I say the word?...of religion. Then I go out at night and paint the stars.

— Carl Sagan

If you wish to make an apple pie from scratch, you must first invent the universe.

— Carl Sagan

Matter is composed chiefly of nothing.

— Carl Sagan

A googolplex is precisely as far from infinity as is the number 1... no matter what number you have in mind, infinity is larger still.

— Carl Sagan

The universe seems neither benign nor hostile, merely indifferent to the concerns of such puny creatures as we are.

— Carl Sagan

Nobody listens to mathematicians.

— 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 neural connections that build an elegant architecture of consciousness.

— Carl Sagan

Other things being equal, it is better to be smart than to be stupid.

— Carl Sagan

War is murder writ large.

— Carl Sagan

We have heard the rationales offered by the nuclear superpowers. We know who speaks for the nations. But who speaks for the human species? Who speaks for Earth?

— Carl Sagan

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.

— Carl Sagan

Those afraid of the universe as it really is, those who pretend to nonexistent knowledge and envision a Cosmos centered on human beings will prefer the fleeting comforts of superstition. They avoid rather than confront the world. But those with the courage to explore the weave and structure of the Cosmos, even where it differs profoundly from their wishes and prejudices, will penetrate its deepest mysteries.

— Carl Sagan

Every one of us is, in the cosmic perspective, precious. If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another.

— Carl Sagan

In the vastness of space and the immensity of time, it is my joy to share a planet and an epoch with Annie.

— Carl Sagan

We are the local embodiment of a Cosmos grown to selfawareness. We have begun to contemplate our origins: starstuff pondering the stars; organized assemblages of ten billion billion billion atoms considering the evolution of atoms; tracing the long journey by which, here at least, consciousness arose. Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring.

— Carl Sagan

I wish to propose a doctrine which may, I fear, appear wildly paradoxical and subversive. The doctrine in question is this: that it is undesirable to believe a proposition when there is no ground whatever for supposing it true. I must, of course, admit that if such an opinion became common it would completely transform our social life and our political system; since both are at present faultless, this must weigh against it.

— Carl Sagan

Humans are good, she knew, at discerning subtle patterns that are really there, but equally so at imagining them when they are altogether absent.

— Carl Sagan

We could not guess how different from us they (extraterrestrials) might be. It was hard enough to guess the intentions of our elected representatives in Washington.

— Carl Sagan

If we like them, they’re freedom fighters, she thought. If we don’t like them, they’re terrorists. In the unlikely case we can’t make up our minds, they’re temporarily only guerrillas.

— Carl Sagan

If the press descended, the science would surely suffer.

— Carl Sagan

If it can be destroyed by the truth, it deserves to be destroyed by the truth.

— Carl Sagan

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

— Carl Sagan

“Let’s see if I’ve got this straight,” he returned. It was a phrase of hers that he had adopted “It’s a lazy Saturday afternoon, and there’s this couple lying naked in bed reading the Encyclopaedia Britannica to each other, and arguing about whether the Andromeda Galaxy is more ‘numinous’ than the Resurrection. Do they know how to have a good time or don’t they?”

— Carl Sagan

Do we, holding that the gods exist,change alone control the world?

— Carl Sagan

The major religions on the Earth contradict each other left and right. You can’t all be correct. And what if all of you are wrong? It’s a possibility, you know. You must care about the truth, right? Well, the way to winnow through all the differing contentions is to be skeptical. I’m not any more skeptical about your religious beliefs than I am about every new scientific idea I hear about. But in my line of work, they’re called hypotheses, not inspiration and not revelation.

— Carl Sagan

Who is more humble? The scientist who looks at the universe with an open mind and accepts whatever the universe has to teach us, or somebody who says everything in this book must be considered the literal truth and never mind the fallibility of all the human beings involved?

— Carl Sagan

What I’m saying is, if God wanted to send us a message, and ancient writings were the only way he could think of doing it, he could have done a better job.

— Carl Sagan

Anything you don’t understand, Mr. Rankin, you attribute to God. God for you is where you sweep away all the mysteries of the world, all the challenges to our intelligence. You simply turn your mind off and say God did it.

— Carl Sagan

Jingoistic rhetoric and puerile self-congratulatory nationalism.

— Carl Sagan

Many harebrained interpretations were also widely available, especially in weekly newspapers.

— Carl Sagan

Spirit” comes from the Latin word “to breathe.” What we breathe is air, which is certainly matter, however thin. Despite usage to the contrary, there is no necessary implication in the word “spiritual” that we are talking of anything other than matter (including the matter of which the brain is made), or anything outside the realm of science. On occasion, I will feel free to use the word. Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light-years and in the passage of ages, when we grasp the intricacy, beauty, and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual. So are our emotions in the presence of great art or music or literature, or of acts of exemplary selfless courage such as those of Mohandas Gandhi or Martin Luther King, Jr. The notion that science and spirituality are somehow mutually exclusive does a disservice to both.

— Carl Sagan

Skepticism is the chastity of the intellect, and it is shameful to surrender it too soon or to the first comer; there is nobility in preserving it coolly and proudly through long youth, until at last, in the ripeness of instinct and discretion, it can be safely exchanged for fidelity and happiness.

— Carl Sagan

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

— Carl Sagan

A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism.

— Carl Sagan

The chiliasts made an atheist out of me.

— Carl Sagan

In Mozambique, the story goes, monkeys do not talk, because they know if they utter even a single word some man will come and put them to work.

— Carl Sagan

“Do you understand what’s going on?”“Not at all,” he shouted back. “I can almost prove this can’t be happening.”

— Carl Sagan

Humans are very good at dreaming, although you’d never know it from your television.

— Carl Sagan

In the long run, the aggressive civilizations destroy themselves, almost always. It’s their nature. They can’t help it.

— Carl Sagan

That it will never come againIs what makes life so sweet.

— Carl Sagan

This planet is run by crazy people. Remember what they have to do to get where they are. Their perspective is so narrow, so...brief. A few years. In the best of them a few decades. They care only about the time they are in power.

— Carl Sagan

Thomas Jefferson and George Washington owned slaves; Albert Einstein and Mohandas Gandhi were imperfect husbands and fathers. The list goes on indefinitely. We are all flawed and creatures of our times. Is it fair to judge us by the unknown standards of the future? Some of the habits of our age will doubtless be considered barbaric by later generations – perhaps for insisting that small children and even infants sleep alone instead of with their parents; or exciting nationalist passions as a means of gaining popular approval and achieving high political office; or allowing bribery and corruption as a way of life; or keeping pets; or eating animals and jailing chimpanzees; or criminalizing the use of euphoriants by adults; or allowing our children to grow up ignorant.

— Carl Sagan

She too had found the experience transforming. How could she not? A demon had been exorcised. Several. And just when she felt more capable of love than she had ever been, she found herself alone.

— Carl Sagan

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

— Carl Sagan

For the first time, we have the power to decide the fate of our planet and ourselves. This is a time of great danger, but our species is young, and curious, and brave. It shows much promise.

— 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.

— Carl Sagan

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

All my life, I've wondered about life beyond the earth. On those countless other planets that we think circle other suns, is there also life? Might the beings of other worlds resemble us, or would they be astonishingly different? What would they be made of? In the vast Milky Way galaxy, how common is what we call life? The nature of life on earth and the quest for life elsewhere are the two sides of the same question: the search for who we are.

— Carl Sagan

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.

— Carl Sagan

The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars.

— Carl Sagan

If it can be destroyed by the truth, it deserves to be destroyed by the truth.

— Carl Sagan

In the vastness of the Cosmos there must be other civilizations far older and more advanced than ours.

— Carl Sagan

What counts is not what sounds plausible, not what we would like to believe, not what one or two witnesses claim, but only what is supported by hard evidence rigorously and skeptically examined. Extraordinary claims require extraordinary evidence.

— Carl Sagan

I am often amazed at how much more capability and enthusiasm for science there is among elementary school youngsters than among college students.

— Carl Sagan

For all I know we may be visited by a different extraterrestrial civilization every second Tuesday, but there's no support for this appealing idea. The extraordinary claims are not supported by extraordinary evidence.

— Carl Sagan

The old man made himself look hard at the Raven and saw that it was not a great bird from the sky but the work of men like himself. This first encounter turned out to be peaceful. The men of the La Pérouse expedition were under strict orders to treat with respect any people they might discover, an exceptional policy for its time and after.

— Carl Sagan

Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light-years and in the passage of ages, when we grasp the intricacy, beauty, and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual. So are our emotions in the presence of great art or music or literature, or of acts of exemplary selfless courage such as those of Mohandas Gandhi or Martin Luther King, Jr. The notion that science and spirituality are somehow mutually exclusive does a disservice to both.

— Carl Sagan

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

Eratosthenes was the director of the great library of Alexandria, the Centre of science and learning in the ancient world. Aristotle had argued that humanity was divided into Greeks and everybody else, whom he called barbarians and that the Greeks should keep themselves racially pure. He thought it was fitting for the Greeks to enslave other peoples. But Eratosthenes criticized Aristotle for his blind chauvinism, he believed there was good and bad in every nation.

— Carl Sagan

History is full of people who out of fear or ignorance or the lust for power have destroyed treasures of immeasurable value which truly belong to all of us. We must not let it happen again.

— Carl Sagan

And we who embody the local eyes and ears and thoughts and feelings of the cosmos we've begun, at last, to wonder about our origins. Star stuff, contemplating the stars organized collections of 10 billion-billion-billion atoms contemplating the evolution of matter tracing that long path by which it arrived at consciousness here on the planet Earth and perhaps, throughout the cosmos.

— Carl Sagan

Science is only a Latin word for knowledge

— Carl Sagan

Our loyalties are to the species and the planet. We speak for Earth. Our obligation to survive and flourish is owed not just to ourselves, but also to that Cosmos, ancient and vast, from which we spring.

— 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

We've tended in our cosmologies to make things familiar. Despite all our best efforts, we've not been very inventive. In the West, Heaven is placid and fluffy, and Hell is like the inside of a volcano. In many stories, both realms are governed by dominance hierarchies headed by gods or devils. Monotheists talked about the king of kings. In every culture we imagined something like our own political system running the Universe. Few found the similarity suspicious.

— Carl Sagan

In some respects, science has far surpassed religion in delivering awe. 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. God must be even greater than we dreamed"? Instead they say, "No, no, no! My god is a little god, and I want him to stay that way."

— Carl Sagan

A scientific colleague tells me about a recent trip to the New Guinea highlands where she visited a stone age culture hardly contacted by Western civilization. They were ignorant of wristwatches, soft drinks, and frozen food. But they knew about Apollo 11. They knew that humans had walked on the Moon. They knew the names of Armstrong and Aldrin and Collins. They wanted to know who was visiting the Moon these days.

— Carl Sagan

I think the discomfort that some people feel in going to the monkey cages at the zoo is a warning sign.

— Carl Sagan

Since, in the long run, every planetary society will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring — not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive.

— Carl Sagan

Imagine we could accelerate continuously at 1 g — what we're comfortable with on good old terra firma — to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars.

— Carl Sagan

The vast distances that separate the stars are providential. Beings and worlds are quarantined from one another. The quarantine is lifted only for those with sufficient self-knowledge and judgement to have safely traveled from star to star.

— Carl Sagan

Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.

— Carl Sagan

If we crave some cosmic purpose, then let us find ourselves a worthy goal.

— Carl Sagan

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

— Carl Sagan

If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits?

— Carl Sagan

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.

— 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

Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science — by far the most successful claim to knowledge accessible to humans — teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us.

— 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

I try not to think with my gut. If I'm serious about understanding the world, thinking with anything besides my brain, as tempting as that might be, is likely to get me into trouble. Really, it's okay to reserve judgment until the evidence is in.

— Carl Sagan

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

If we keep on with business as usual, the Earth will be warmed more every year; drought and floods will be endemic; many more cities, provinces, and whole nations will be submerged beneath the waves — unless heroic worldwide engineering countermeasures are taken. In the longer run, still more dire consequences may follow, including the collapse of the West Antarctic ice sheet, and the inundation of almost all the coastal cities on the planet.

— Carl Sagan

A central lesson of science is that to understand complex issues (or even simple ones), we must try to free our minds of dogma and to guarantee the freedom to publish, to contradict, and to experiment. Arguments from authority are unacceptable.

— Carl Sagan

So those who wished for some central cosmic purpose for us, or at least our world, or at least our solar system, or at least our galaxy, have been disappointed, progressively disappointed. The universe is not responsive to our ambitious expectations.

— Carl Sagan

Widespread intellectual and moral docility may be convenient for leaders in the short term, but it is suicidal for nations in the long term. One of the criteria for national leadership should therefore be a talent for understanding, encouraging, and making constructive use of vigorous criticism.

— Carl Sagan

Superstition is marked not by its pretension to a body of knowledge but by its method of seeking truth.

— Carl Sagan

I stress that the universe is made mostly of nothing, that something is the exception.

— Carl Sagan

This vast number of worlds, the enormous scale of the universe... has not been taken into account, even superficially, in virtually no religion, and especially in no Western religions.

— Carl Sagan

Many religions have attempted to make statues of their gods very large, and the idea, I suppose, is to make us feel small. But if that's their purpose, they can keep their paltry icons. We need only look up if we wish to feel small.

— Carl Sagan

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark.

— Carl Sagan

In many myths, the one possibility the gods are most anxious about is that humans will discover some secret of immortality or even... attempt to stride the high heavens. ...It's a little bit like the rich imposing poverty on the poor and then asking to be loved because of it.

— Carl Sagan

A general problem with much of Western theology... is that the God portrayed is too small. It is a god of a tiny world and not a god of a galaxy, much less a universe.

— Carl Sagan

If we seek... nature, then love can be informed by truth instead of being based on ignorance or self-deception.

— Carl Sagan

If a Creator God exists, would He or She or It... prefer a kind of sodden blockhead who worships while understanding nothing? Or would He prefer His votaries to admire the real universe in all its intracacy?

— Carl Sagan

Science is, at least in part, informed worship.

— Carl Sagan

The enterprise of knowledge is consistent surely with science; it should be with religion, and it is essential for the welfare of the human species.

— Carl Sagan

The idea that as I walk in this direction my watch goes slightly slower and I am contracted in the direction of motion and my mass has increased slightly does not correspond to everyday experience. ...the reason that it does not correspond to common sense is that we are not in the habit of traveling close to the speed of light. We may one day be in that habit, and then the Lorentz transformations will be natural, intuitive.

— Carl Sagan

If I were to propose to you that my arm could be in this position or in that position but it would be forbidden by the laws of nature to be in some intermediate position, that would likely strike you as absurd, as contrary to experience. And yet on the subatomic level, there is a quantization of energy and position and momentum. The reason that it seems counterintuitive is that is that we are not ordinarily down at the level of the very small, where quantum effects dominate.

— Carl Sagan

The history of science—especially physics—has in part been the tension between the natural tendency to project our everyday experience on the universe and the universe's noncompliance...

— Carl Sagan

Projected upon the natural world... is the idea of privilege. ...Ever since the invention of civilization, there have been privileged classes... some groups that oppress others and that work to maintain these heirarchies of power. The children of the privileged grow up expecting that, through no particular effort of their own, they will retain a privileged position.

— Carl Sagan

At birth all of us imagine that we are the universe, and we don't distinguish the boundaries between ourselves and those around us. ...in some social situations, there is the sense that we are central, important. ...there was a natural projection of those attitudes upon the universe.

— Carl Sagan

Once upon a time, the best minds of the human species believed that the planets were attached to crystal spheres. ...Both in classic and in medieval times, it was prominently speculated that gods or angels propelled them, gave them a twirl every now and then. The Newtonian gravitational superstructure replaced angels with GMm/r... as science advances, there seems to be less and less for God to do.

— Carl Sagan

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

— Carl Sagan

Evolving before our eyes has been a God of the Gaps; that is, whatever it is we cannot explain lately is attributed to God.

— Carl Sagan

Suppose your father... walked into this room at the ordinary human pace of walking. And suppose just behind him was his father. How long would we have to wait before the ancestor who enters the now-open door is a creature who normally walked on all fours? The answer is a week.

— Carl Sagan

This image of four spectra is taken from one of Huggins's publications. ...You can see that the Comet Winnecke resembles olive oil more than it does Comet Brorsen.

— Carl Sagan

We find a set of data that strongly implies the presence of complex organic molecules in the outer solar system.

— Carl Sagan

Carbonaceous meteorites that fall to the Earth... have several percent to as much as 10 percent of complex organic matter in them.

— Carl Sagan

This is Phobos... Its mean density is known, and it is consistent with organic matter. Deimos... same story.

— Carl Sagan

There is a very stunning range of studies... of interstellar organic matter... the cold, dark spaces between the stars are also loaded with organic matter. ...complex organic materials are everywhere.

— Carl Sagan

The amount of organic matter that could have been produced in the first few hundred million years of Earth history was sufficient to have produced in the present ocean a several-percent solution of organic matter. This is just about the dilution of Knorr's chicken soup, and not that different from the composition either. And chicken soup is widely known to be good for life.

— Carl Sagan

The origin of life happened in significantly less than 500 million years. ...Six days was once a popular hypothesis. ...A process that happens quickly is a process that is in some sense likely... this evidence suggests that the origin of life was in some sense easy, in some sense sitting in the laws of physics and chemistry.

— Carl Sagan

If there's nothing in here but atoms, does that make us less or does that make matter more?

— Carl Sagan

Let's say there's a molecule that produces a religious experience... a natural molecule that the body produces whose function it is to produce religious experiences, at least on occasion? ...So let's call it "theophorin"...What could the selective advantage of theophorin be? ...to suit us for the quest that was, according to Dostoyevsky, to strive for nothing so incessantly and so painfully as to find someone to worship and obey.

— Carl Sagan

There is no question that religions have historically played the role of making people contented with their lot. ...such a doctrine would be very appealing to the ruling classes of a society. ...Many societies, for this reason alone, encourage the contentment with your lot that the religious premise of heaven affords.

— Carl Sagan

Many religions lay out a set of precepts... and claim that these instructions were given by a god or gods. For example, the first code of law by Hammurabi of Babylon... was handed to him by the god Marduk... this is a bamboozle... a pious hoax. ...if Hammurabi had merely said, "Here's what I think everybody should do," he would have been much less successful...

— Carl Sagan

There is in the lovely Martian landscape not a footprint, not an artifact, not even an old beer can, not a blade of grass, not a kangaroo rat, not even, so far as we can tell, a microbe. Mars and the Moon and Venus... the only planets that we've landed on—are utterly lifeless. ...in our solar system we may discover that there is life only on this world. This says that life is not guaranteed, that life requires something special, something improbable.

— Carl Sagan

Because it is clear from the fossil record that almost every species that has ever existed is extinct; extinction is the rule, survival is the exception.

— Carl Sagan

The cosmos is full beyond measure of elegant truths; of exquisite interrelationships; of the awesome machinery of nature. The surface of the Earth is the shore of the cosmic ocean. On this shore we've learned most of what we know. Recently we've waded a little way out, maybe ankle deep, and the water seems inviting. Some part of our being knows this is where we came from. We long to return. And we can. Because the cosmos is also within us. We're made of star-stuff. We are a way for the cosmos to know itself.

— Carl Sagan

The prediction I can make with the highest confidence is that the most amazing discoveries will be the ones we are not today wise enough to foresee.

— Carl Sagan

The whole idea of what happens when you read a book, I find absolutely stunning. Here's some product of a tree, little black squiggles on it, you open it up, an inside your head is the voice of someone speaking, who may have been dead 3000 years, and there he is talking directly to you, what a magical thing that is.

— Carl Sagan

When there isn't enough food, the body has to make a decision on how to invest the limited foodstuff available to it. Survival comes first, growth comes second. And in this kind of nutritional triage, the body seems obliged to rank learning, last. It sort of it's better to be stupid and alive, than smart and dead.

— Carl Sagan

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

— Carl Sagan

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.

— Carl Sagan

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

— Carl Sagan

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

— Carl Sagan

If you wish to make an apple pie from scratch, you must first invent the 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 are the representatives of the cosmos; we are an example of what hydrogen atoms can do, given 15 billion years of cosmic evolution.

— Carl Sagan

The universe seems neither benign nor hostile, merely indifferent.

— Carl Sagan

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark.

— 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

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

— 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

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

— Carl Sagan

We've arranged a civilization in which most crucial elements profoundly depend on science and technology.

— Carl Sagan

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

— Carl Sagan

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.

— Carl Sagan

If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits?

— Carl Sagan

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?

— Carl Sagan

A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism.

— Carl Sagan

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

— Carl Sagan

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

— Carl Sagan

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

— Carl Sagan

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

— Carl Sagan

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.

— 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

Absence of evidence is not evidence of absence.

— Carl Sagan

Extinction is the rule. Survival is the exception.

— Carl Sagan

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

— Carl Sagan

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.

— Carl Sagan

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.

— Carl Sagan

The universe is not required to be in perfect harmony with human ambition.

— Carl Sagan

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.

— Carl Sagan

Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light‐years and in the passage of ages, when we grasp the intricacy, beauty, and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual. So are our emotions in the presence of great art or music or literature, or acts of exemplary selfless courage such as those of Mohandas Gandhi or Martin Luther King, Jr. The notion that science and spirituality are somehow mutually exclusive does a disservice to both.

— Carl Sagan

The Earth is a very small stage in a vast cosmic arena.

— Carl Sagan

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.

— Carl Sagan

I am often amazed at how much more capability and enthusiasm for science there is among elementary school youngsters than among college students.

— Carl Sagan

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.

— Carl Sagan

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

— Carl Sagan

Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works.

— Carl Sagan

For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.

— Carl Sagan

I can find in my undergraduate classes, bright students who do not know that the stars rise and set at night, or even that the Sun is a star.

— Carl Sagan

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.

— Carl Sagan

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

— Carl Sagan

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.

— Carl Sagan

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!

— Carl Sagan

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.

— Carl Sagan

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

— Carl Sagan

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.

— Carl Sagan

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.

— Carl Sagan

It goes with a courageous intent to greet the universe as it really is, not to foist our emotional predispositions on it but to courageously accept what our explorations tell us.

— Carl Sagan

Imagine, a room, awash in gasoline. And there are two implacable enemies in that room. One of them has 9,000 matches. The other has 7,000 matches. Each of them is concerned about who’s ahead, who’s stronger. Well, that's the kind of situation we are actually in. The amount of weapons that are available to the United States and the Soviet Union are so bloated, so grossly in excess of what's needed to dissuade the other that if it weren't so tragic, it would be laughable.

— 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

We live in a society absolutely dependent on science and technology and yet have cleverly arranged things so that almost no one understands science and technology. That's a clear prescription for disaster.

— Carl Sagan

The idea that God is an oversized white male with a flowing beard who sits in the sky and tallies the fall of every sparrow is ludicrous. But if by God one means the set of physical laws that govern the universe, then clearly there is such a God. This God is emotionally unsatisfying... it does not make much sense to pray to the law of gravity.

— Carl Sagan

Every kid starts out as a natural-born scientist, and then we beat it out of them. A few trickle through the system with their wonder and enthusiasm for science intact.

— Carl Sagan

Something dreadful happens to students between first and twelfth grades, and it's not just puberty.

— Carl Sagan

That kind of skeptical, questioning, "don't accept what authority tells you" attitude of science — is also nearly identical to the attitude of mind necessary for a functioning democracy. Science and democracy have very consonant values and approaches, and I don't think you can have one without the other.

— Carl Sagan

The many sorrows of our recent history suggest that we humans have a learning disability.

— Carl Sagan

Who is more humble? The scientist who looks at the universe with an open mind and accepts whatever it has to teach us, or somebody who says everything in this book must be considered the literal truth and never mind the fallibility of all the human beings involved?

— Carl Sagan

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.

— Carl Sagan

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

— Carl Sagan

The cannabis experience has greatly improved my appreciation for art, a subject which I had never much appreciated before. The understanding of the intent of the artist which I can achieve when high sometimes carries over to when I'm down. This is one of many human frontiers which cannabis has helped me traverse. There also have been some art-related insights — I don't know whether they are true or false, but they were fun to formulate.

— 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

Cannabis also enhances the enjoyment of sex — on the one hand it gives an exquisite sensitivity, but on the other hand it postpones orgasm: in part by distracting me with the profusion of image passing before my eyes. The actual duration of orgasm seems to lengthen greatly, but this may be the usual experience of time expansion which comes with cannabis smoking.

— Carl Sagan

I proffer the following ideas with a substantial degree of trepidation; I know very well that many of them are speculative and can be proved or disproved on the anvil of experiment.

— Carl Sagan

My fundamental premise about the brain is that its workings—what we sometimes call “mind”—are a consequence of its anatomy and physiology, and nothing more.

— Carl Sagan

Absence of evidence is not evidence of absence.

— Carl Sagan

The entire recent history of biology shows that we are, to a remarkable degree, the results of the interactions of an extremely complex array of molecules; and the aspect of biology that was once considered its holy of holies, the nature of the genetic material, has now been fundamentally understood in terms of the chemistry of its constituent nucleic acids, DNA and RNA, and their operational agents, the proteins.

— Carl Sagan

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

— Carl Sagan

Those at too great a distance may, I am well aware, mistake ignorance for perspective.

— Carl Sagan

At any rate, both because of the clear trend in the recent history of biology and because there is not a shred of evidence to support it, I will not in these pages entertain any hypotheses on what used to be called the mind-body dualism, the idea that inhabiting the matter of the body is something made of quite different stuff, called mind.

— Carl Sagan

It is important to distinguish between the amount of information and the quality of that information.

— Carl Sagan

A mutation in a DNA molecule within a chromosome of a skin cell in my index finger has no influence on heredity. Fingers are not involved, at least directly, in the propagation of the species.

— Carl Sagan

Note that in all this interaction between mutation and natural selection, no moth is making a conscious effort to adapt to a changed environment. The process is random and statistical.

— 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

There is a popular contention that half or more of the brain is unused. From an evolutionary point of view this would be quite extraordinary: why should it have evolved if it had no function? But actually the statement is made on very little evidence.

— Carl Sagan

The price we pay for the anticipation of our future is anxiety about it. Foretelling disaster is probably not much fun; Pollyanna was much happier than Cassandra. But the Cassandric components of our nature are necessary for survival.

— Carl Sagan

Evolution often uses this strategy. Indeed, the standard evolutionary practice of increasing the amount of genetic information as organisms increase in complexity is accomplished by doubling part of the genetic material and then allowing the slow specialization of function of the redundant set.

— Carl Sagan

There is no doubt that right-hemisphere intuitive thinking may perceive patterns and connections too difficult for the left hemisphere; but it may also detect patterns where none exist. Skeptical and critical thinking is not a hallmark of the right hemisphere. And unalloyed right-hemisphere doctrines, particularly when they are invented during new and trying circumstances, may be erroneous or paranoid.

— Carl Sagan

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.

— Carl Sagan

There is no way to tell whether the patterns extracted by the right hemisphere are real or imagined without subjecting them to left-hemisphere scrutiny. On the other hand, mere critical thinking, without creative and intuitive insights, without the search for new patterns, is sterile and doomed. To solve complex problems in changing circumstances requires the activity of both cerebral hemispheres: the path to the future lies through the corpus callosum.

— Carl Sagan

The search for patterns without critical analysis, and rigid skepticism without a search for patterns, are the antipodes of incomplete science. The effective pursuit of knowledge requires both functions.

— Carl Sagan

Without these experimental tests, very few physicists would have accepted general relativity. There are many hypotheses in physics of almost comparable brilliance and elegance that have been rejected because they did not survive such a confrontation with experiment. In my view, the human condition would be greatly improved if such confrontations and willingness to reject hypotheses were a regular part of our social, political, economic, religious and cultural lives.

— Carl Sagan

Anatomy is not destiny, but it is not irrelevant either.

— Carl Sagan

The integrity of the experimenters in the face of this unexpected finding is breathtaking. (It is difficult to imagine any experiment that would convince leading practitioners of many political or religious philosophies of the superiority of a competing doctrine.)

— Carl Sagan

To me it is not in the least demeaning that consciousness and intelligence are the result of “mere” matter sufficiently complexly arranged; on the contrary, it is an exalting tribute to the subtlety of matter and the laws of Nature.

— Carl Sagan

That in nonarithmetic operations the small and slow human brain can still do so much better than the large and fast electronic computer is an impressive tribute to how cleverly the brain is packaged and programmed—features brought about, of course, by natural selection. Those who possessed poorly programmed brains eventually did not live long enough to reproduce.

— Carl Sagan

The entire evolutionary record on our planet, particularly the record contained in fossil endocasts, illustrates a progressive tendency toward intelligence. There is nothing mysterious about this: smart organisms by and large survive better and leave more offspring than stupid ones.

— Carl Sagan

Once intelligent beings achieve technology and the capacity for self-destruction of their species, the selective advantage of intelligence becomes more uncertain.

— Carl Sagan

Natural selection has served as a kind of intellectual sieve, producing brains and intelligences increasingly competent to deal with the laws of nature. This resonance, extracted by natural selection, between our brains and the universe may help explain a quandary set by Einstein: The most incomprehensible property of the universe, he said, is that it is so comprehensible.

— 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

Broca was quoted as saying, “I would rather be a transformed ape than a degenerate son of Adam.”

— Carl Sagan

Society corrupts the best of us. It is a little unfair, I think, to criticize a person for not sharing the enlightenment of a later epoch, but it is also profoundly saddening that such prejudices were so extremely pervasive. The question raises nagging uncertainties about which of the conventional truths of our own age will be considered unforgivable bigotry by the next.

— Carl Sagan

People are rarely grateful for a demonstration of their credulity.

— Carl Sagan

Both Barnum and H. L. Mencken are said to have made the depressing observation that no one ever lost money by underestimating the intelligence of the American public. The remark has worldwide application. But the lack is not in intelligence, which is in plentiful supply; rather, the scarce commodity is systematic training in critical thinking.

— Carl Sagan

For many people, the shoddily thought out doctrines of borderline science are the closest approximation to comprehensible science readily available. The popularity of borderline science is a rebuke to the schools, the press and commercial television for their sparse, unimaginative and ineffective efforts at science education; and to us scientists, for doing so little to popularize our subject.

— Carl Sagan

Very few scientists actually plunge into the murky waters of testing or challenging borderline or pseudo-scientific beliefs. The chance of finding out something really interesting—except about human nature—seems small, and the amount of time required seems large. I believe that scientists should spend more time in discussing these issues, but the fact that a given contention lacks vigorous scientific opposition in no way implies that scientists think it is reasonable.

— Carl Sagan

I believe that the extraordinary should certainly be pursued. But extraordinary claims require extraordinary evidence.

— Carl Sagan

The best antidote for pseudoscience, I firmly believe, is science.

— Carl Sagan

The idea of science as a method rather than as a body of knowledge is not widely appreciated outside of science, or indeed in some corridors inside of science.

— Carl Sagan

Vigorous criticism is more constructive in science than in some other areas of human endeavor because in science there are adequate standards of validity that can be agreed upon by competent practitioners the world over. The objective of such criticism is not to suppress but rather to encourage the advance of new ideas: those that survive a firm skeptical scrutiny have a fighting chance of being right, or at least useful.

— Carl Sagan

It is merely a coincidence. When enough fiction is written and enough scientific hypotheses are proposed, sooner or later there will be accidental concordances.

— Carl Sagan

St. Anselm argued that since we can imagine a perfect being, he must exist—because he would not be perfect without the added perfection of existence. This so-called ontological argument was more or less promptly attacked on two grounds: (1) Can we imagine a completely perfect being? (2) Is it obvious that perfection is augmented by existence? To the modern ear such pious arguments seem to be about words and definitions rather than about external reality.

— Carl Sagan

Many scientists deeply involved in the exploration of the solar system (myself among them) were first turned in that direction by science fiction. And the fact that some of that science fiction was not of the highest quality is irrelevant. Ten-year-olds do not read the scientific literature.

— Carl Sagan

Every new set of discoveries raises a host of questions which we were never before wise enough even to ask.

— Carl Sagan

Much of human history can, I think, be described as a gradual and sometimes painful liberation from provincialism, the emerging awareness that there is more to the world than was generally believed by our ancestors.

— Carl Sagan

The search for extraterrestrial intelligence is the search for a generally acceptable cosmic context for the human species. In the deepest sense, the search for extraterrestrial intelligence is a search for ourselves.

— Carl Sagan

Whether we believe in God depends very much on what we mean by God.

— Carl Sagan

A clear prediction in an area undergoing vigorous study permits doctrines to be subject to disproof. The last posture a bureaucratic religion wishes to find itself in is vulnerability to disproof, where an experiment can be performed on which the religion stands or falls.

— Carl Sagan

The idea that a God or gods is necessary to effect one or more of these origins has been under repeated attack over the last few thousand years. Because we know something about phototropism and plant hormones, we can understand the opening of the morning glory independent of divine microintervention. It is the same for the entire skein of causality back to the origin of the universe. As we learn more and more about the universe, there seems less and less for God to do.

— Carl Sagan

But there is a chance that the answers will discomfit a great many bureaucratic and doctrinal religions. The idea of religion as a body of belief, immune to criticism, fixed forever by some founder is, I think, a prescription for the long-term decay of the religion, especially lately.

— Carl Sagan

The way to find out about our place in the universe is by examining the universe and by examining ourselves—without preconceptions, with as unbiased a mind as we can muster. We cannot begin with an entirely clean slate, since we arrive at this problem with predispositions of hereditary and environmental origin; but, after understanding such built-in biases, is it not possible to pry insights from nature?

— Carl Sagan

It is a good idea not to make up our minds prematurely on this issue. It is probably best not to let our personal preferences influence the decision. Rather, in the long tradition of successful science, we should permit nature to reveal the truth to us.

— Carl Sagan

In any case, we do not advance the human cause by refusing to consider ideas that make us frightened.

— Carl Sagan

We are set irrevocably, I believe, on a path that will take us to the stars—unless in some monstrous capitulation to stupidity and greed, we destroy ourselves first.

— Carl Sagan

In the vastness of space and the immensity of time, it is my joy to share a planet and an epoch with Annie.

— Carl Sagan

The Cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us — there is a tingling in the spine, a catch in the voice, a faint sensation as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries.

— Carl Sagan

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

— Carl Sagan

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

— Carl Sagan

We are like butterflies who flutter for a day and think it's forever.

— Carl Sagan

The fossil record implies trial and error, an inability to anticipate the future, features inconsistent with an efficient Great Designer.

— Carl Sagan

If a marker were to be erected today, it might read, in homage to his scientific courage: “He preferred the hard truth to his dearest illusions.”

— Carl Sagan

When I wake up I go through an abbreviated process of mourning all over again. Plainly, there’s something within me that’s ready to believe in life after death. And it’s not the least bit interested in whether there’s any sober evidence for it.

— Carl Sagan

It is all a matter of time scale. An event that would be unthinkable in a hundred years may be inevitable in a hundred million.

— Carl Sagan

The suppression of uncomfortable ideas may be common in religion and politics, but it is not the path to knowledge; it has no place in the endeavor of science.

— Carl Sagan

With insufficient data it is easy to go wrong.

— Carl Sagan

Human beings have a demonstrated talent for self-deception when their emotions are stirred.

— Carl Sagan

For a long time the human instinct to understand was thwarted by facile religious explanations.

— Carl Sagan