Sagan Carl Quotes & Sayings

There is a mathematical underpinning that you must first acquire, mastery of each mathematical subdiscipline leading you to the threshold of the next. In turn you must learn arithmetic, Euclidian geometry, high school algebra, differential and integral calculus, ordinary and partial differential equations, vector calculus, certain special functions of mathematical physics, matrix algebra, and group theory. For most physics students, this might occupy them from, say, third grade to early graduate school - roughly 15 years. Such a course of study does not actually involve learning any quantum mechanics, but merely establishing the mathematical framework required to approach it deeply. — Carl Sagan

Part of the success of the tobacco industry in purveying this brew of addictive poisons can be attributed to widespread unfamiliarity with baloney detection, critical thinking, and the scientific method. Gullibility kills. — Carl Sagan

Across the sea of space, the stars are other suns. — Carl Sagan

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

All civilizations become either spacefaring or extinct. — Carl Sagan

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. — Carl Sagan

Science is far from a perfect instrument of knowledge. It's just the best we have. In this respect, as in many others, it's like democracy. Science by itself cannot advocate courses of human action, but it can certainly illuminate the possible consequences of alternative courses of action. — Carl Sagan

I'm frequently asked, "Do you believe there's extraterrestrial intelligence?" I give the standard arguments- there are a lot of places out there, the molecules of life are everywhere, I use the word billions, and so on. Then I say it would be astonishing to me if there weren't extraterrestrial intelligence, but of course there is as yet no compelling evidence for it.
Often, I'm asked next, "What do you really think?"
I say, "I just told you what I really think."
"Yes, but what's your gut feeling?"
But 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

Sagan is an astronomer with one eye on the stars, another on history, and a third - his mind's - on the human condition. ... — Carl Sagan

I know of no significant advance in science that did not require major inputs from both cerebral hemispheres. This is not true for art, where apparently there are no experiments by which capable, dedicated and unbiased observers can determine to their mutual satisfaction which works are great. — 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

Science is more than a body of knowledge. It is a way of thinking; a way of skeptically interrogating the universe with a fine understanding of human fallibility.
If we are not able to ask skeptical questions, to interrogate those who tell us that something is true, to be skeptical of those in authority, then, we are up for grabs for the next charlatan (political or religious) who comes rambling along. — Carl Sagan

In college, in the early 1950s, I began to learn a little about how science works, the secrets of its great success, how rigorous the standards of evidence must be if we are really to know something is true, how many false starts and dead ends have plagued human thinking, how our biases can colour our interpretation of evidence, and how often belief systems widely held and supported by the political, religious and academic hierarchies turn out to be not just slightly in error, but grotesquely wrong. — Carl Sagan

Who will speak for Planet Earth? — Carl Sagan

Ten long trips around the sun since I last saw that smile, but only joy and thankfulness that on a tiny world in the vastness, for a couple of moments in the immensity of time, we were one. — Ann Druyan

Thus, 99 percent of the Earth's atmosphere is of biological origin. The sky is made by life. — Carl Sagan

Humans are very good at dreaming, although you'd never know it from your television. — Carl Sagan

The Yale anthropologist Weston La Barre goes far as to argue that 'a surprisingly good case could be made that much of culture is hallucination' and that 'the whole intent and function of ritual appears to be... a group wish to hallucinate reality'. — Carl Sagan

Coal, oil and gas are called fossil fuels, because they are mostly made of the fossil remains of beings from long ago. The chemical energy within them is a kind of stored sunlight originally accumulated by ancient plants. Our civilization runs by burning the remains of humble creatures who inhabited the Earth hundreds of millions of years before the first humans came on the scene. Like some ghastly cannibal cult, we subsist on the dead bodies of our ancestors and distant relatives. — 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

Evolution is adventitious and not foresighted. Only through the deaths of an immense number of slightly maladapted organisms are we, brains and all, here today. — Carl Sagan

We are made of star stuff. For the most part, atoms heavier than hydrogen were created in the interiors of stars and then expelled into space to be incorporated into later stars. The Sun is probably a third generation star. — Carl Sagan

You're an interesting species. An interesting mix. You're capable of such beautiful dreams, and such horrible nightmares. You feel so lost, so cut off, so alone, only you're not. See, in all our searching, the only thing we've found that makes the emptiness bearable, is each other. — Carl Sagan

The Big Bang is our modern scientific creation myth. It comes from the same human need to solve the cosmological riddle [Where did the universe come from?] — Carl Sagan

Our ancestors worshipped the Sun, and they were not that foolish. It makes sense to revere the Sun and the stars, for we are their children. — Carl Sagan

Nearly everyone in ancient Egypt exhorted the gods to let the Pharaoh live 'forever. These collective prayers failed. Their failure constitutes data. — Carl Sagan

But the brain does much more than just recollect it inter-compares, it synthesizes, it analyzes, it generates abstractions. The simplest thought like the concept of the number one has an elaborate logical underpinning. The brain has its own language for testing the structure and consistency of the world. — 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

We live in an in-between universe where things change all right ... but according to patterns, rules, or as we call them, laws of nature. — Carl Sagan

[an encounter in space] Some celestial event. No
no words
no words to describe it. Poetry! They should have sent a poet. So beautiful. So beautiful ... I had no idea. I had no idea. — Carl Sagan

The sleeping style of each organism is exquisitely
adapted to the ecology of the animal. It is conceivable that animals who are too stupid to be quiet on their own initiative are, during periods of high risk, immobilized by the implacable arm of sleep. — 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

In the way that scepticism is sometimes applied to issues of public concern, there is a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superstition and pseudoscience are human beings with real feelings, who, like the sceptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped. — 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 uniqueness of humans has been claimed on many grounds, but most often because of our tool-making, culture, language, reason and morality. We have them, the other animals don't, and
so the argument goes
that's that. — Carl Sagan

If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another. Human — Carl Sagan

The whole idea of a democratic application of skepticism is that everyone should have the essential tools to effectively and constructively evaluate claims to knowledge. — Carl Sagan

An atheist has to know a lot more than I know. An atheist is someone who knows there is no god. By some definitions atheism is very stupid. — Carl Sagan

There are as many atoms in one molecule of DNA as there are stars in a typical galaxy. — Carl Sagan

In our time we have less severe standards. We tell children about Santa Claus, the Easter Bunny, and the Tooth Fairy for reasons we think emotionally sound, but then disabuse them of these myths before they're grown. Why retract? Because their well-being as adults depends on them knowing the world as it really is. We worry, and for good reason, about adults who still believe in Santa Claus. — Carl Sagan

Human spoken language seems to be
adventitious. The exploitation of organ systems with other functions for communication in humans is also indicative of the comparatively recent evolution of our linguistic abilities. — Carl Sagan

For all the tenure of humans on Earth, the night sky had been a companion and an inspiration. The stars were comforting. They seemed to demonstrate that the heavens were created for the benefit and instruction of humans. This pathetic conceit became the conventional wisdom worldwide. No culture was free of it. Some people found in the skies an aperture to the religious sensibility. Many were awestruck and humbled by the glory and scale of the cosmos. Others were stimulated to the most extravagant flights of fancy. — Carl Sagan

I think that when you consider the beauty of the world and you wonder how it came to be what it is, you are naturally overwhelmed with a feeling of awe, a feeling of admiration and you almost feel a desire to worship something. I feel this, I recognise that other scientists such as Carl Sagan feel this, Einstein felt it. We, all of us, share a kind of religious reverence for the beauties of the universe, for the complexity of life. For the sheer magnitude of the cosmos, the sheer magnitude of geological time. And it's tempting to translate that feeling of awe and worship into a desire to worship some particular thing, a person, an agent. You want to attribute it to a maker, to a creator. What science has now achieved is an emancipation from that impulse to attribute these things to a creator.
God Delusion debate Professor Richard Dawkins vs John Lennox — Richard Dawkins

I maintain there is much more wonder in science than in pseudoscience. And in addition, to whatever measure this term has any meaning, science has the additional virtue, and it is not an inconsiderable one, of being true. — Carl Sagan

Much more plausible is the computer-based explanation that dreams are a spillover from the unconscious processing of the day's experience, from the brain's decision on how much of the daily events temporarily stored in a kind of buffer to emplace in long-term memory... The American psychiatrist Ernest Hartmann of Tufts University has provided
anecdotal but reasonably persuasive evidence that people who are engaged in intellectual activities during the day, especially unfamiliar intellectual activities, require more sleep at night, while, by and large, those engaged in mainly repetitive and intellectually unchallenging tasks are able to do with much less sleep. — Carl Sagan

The Cosmos extends, for all practical purposes, forever. After a brief sedentary hiatus, we are resuming our ancient nomadic way of life. Our remote descendants, safely arrayed on many worlds throughout the Solar System and beyond, will be unified by their common heritage, by their regard for their home planet, and by the knowledge that, whatever other life may be, the only humans in all the Universe come from Earth. They will gaze up and strain to find the blue dot in their skies. They will love it no less for its obscurity and fragility. They will marvel at how vulnerable the repository of all our potential once was, how perilous our infancy, how humble our beginnings, how many rivers we had to cross before we found our way. — Carl Sagan

Significant change might require those who are now high in the hierarchy to move downward many steps. This seems to them undesirable and is resisted. — Carl Sagan

There is every reason to think that in the coming years Mars and its mysteries will become increasingly familiar to the inhabitants of the Planet Earth. — Carl Sagan

Or consider a story in the Jewish Talmud left out of the Book of Genesis. (It is in doubtful accord with the account of the apple, the Tree of Knowledge, the Fall, and the expulsion from Eden.) In The Garden, God tells Eve and Adam that He has intentionally left the Universe unfinished. It is the responsibility of humans, over countless generations, to participate with God in a "glorious" experiment - the "completing of the Creation."
The burden of such a responsibility is heavy, especially on so weak and imperfect a species as ours, one with so unhappy a history. Nothing remotely like "completion" can be attempted without vastly more knowledge than we have today. But, perhaps, if our very existence is at stake, we will find ourselves able to rise to this supreme challenge. — 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

If prayer works, why can't God cure cancer or grow back a severed limb? Why so much avoidable suffering that God could so readily prevent? Why does God have to be prayed to at all? Doesn't He already know what cures need to be performed? Dossey also begins with a quote from Stanley Krippner, M.D. (described as "one of the most authoritative investigators of the variety of unorthodox healing methods used around the world"): [T]he research data on distant, prayer-based healing are promising, but too sparse to allow any firm conclusion to be drawn. This after many trillions of prayers over the millennia. — Carl Sagan

Perhaps for the first time in any medium, the person teaching you science - Carl Sagan - cared about the tangled mental roadways that can rob a person of rational thought. — Carl Sagan

Often, superstition and injustice are imposed by the same ecclesiastical and secular authorities, working hand in glove. It is no surprise that political revolutions, scepticism about religion, and the rise of science might go together, — Carl Sagan

Which aspects of our nature will prevail is uncertain, particularly when our visions and prospects are bound to one small part of the small planet Earth. But up there in the Cosmos an inescapable perspective awaits. — Carl Sagan

Not explaining science seems to me perverse. When you're in love, you want to tell the world. — Carl Sagan

Is it fair to be suspicious of an entire profession because of a few bad apples? There are at least two important differences, it seems to me. First, no one doubts that science actually works, whatever mistaken and fraudulent claim may from time to time be offered. But whether there are any miraculous cures from faith-healing, beyond the body's own ability to cure itself, is very much at issue. Secondly, the expose' of fraud and error in science is made almost exclusively by science. But the exposure of fraud and error in faith-healing is almost never done by other faith-healers. — Carl Sagan

It means nothing to be open to a proposition we don't understand. — Carl Sagan

The values of science and the values of democracy are concordant, in many cases indistinguishable. — Carl Sagan

The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land. - T. H. Huxley, — Carl Sagan

To live in the hearts of others is to never die in those we leave behind. — Carl Sagan

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

Telepathy' literally means to feel at a distance, just as 'telephone' is to hear at a distance and 'television' is to see at a distance. The word suggests the communication not of thoughts but of feelings, emotions. Around a quarter of all Americans believe they've experienced something like telepathy. People who know each other very well, who live together, who are practised in one another's feeling tones, associations and thinking styles can often anticipate what the partner will say. This is merely the usual five senses plus human empathy, sensitivity and intelligence in operation. It may feel extrasensory, but it's not at all what's intended by the word 'telepathy'. If something like this were ever conclusively demonstrated, it would, I think, have discernible physical causes -perhaps electrical currents in the brain. Pseudoscience, rightly or wrongly labelled, is by no means the same thing as the supernatural, which is by definition something somehow outside of Nature. — Carl Sagan

But the male lexicographers had somehow neglected to coin a word for the dislike of men. They were almost entirely men themselves, she thought, and had been unable to imagine a market for such a word. — Carl Sagan

Our difficulties in understanding or effectuating
communication with other animals may arise from our reluctance to grasp unfamiliar ways of dealing with the world. — Carl Sagan

Every thinking person fears nuclear war, and every technological state plans for it.
Everyone knows it is madness, and every nation has an excuse — Carl Sagan

If there is as a continuum from self-reproducing molecules, such as DNA, to microbes, and an evolutionary sequence continuum from microbes to humans, why should we imagine that continuum to stop at humans? — 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

At the extremes it is difficult to distinguish pseudoscience from rigid, doctrinaire religion. — Carl Sagan

In the littered field of discredited self-congratulatory chauvinisms, there is only one that seems to hold up, one sense in which we are special: Due to our own actions or inactions, and the misuse of our technology, we live at an extraordinary moment, for the Earth at least - the first time that a species has become able to wipe itself out. — Carl Sagan

In every such society, there is a cherished world of myth and metaphor which co-exists with the workaday world. Efforts to reconcile the two are made, and any rough edges at the joints tend to be off-limits and ignored. We compartmentalize. Some scientists do this too, effortlessly stepping between the skeptical world of science and the credulous world of religious belief without skipping a beat. Of course, the greater the mismatch between these two worlds, the more difficult it is to be comfortable, with untroubled conscience, with both. — Carl Sagan

Do whales know each other's names? Can they recognise each other as individuals by sounds alone? We have cut the whales off from themselves. Creatures that communicated for tens of millions of years have now effectively been silenced. — 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

The open road still softly calls ... — Carl Sagan

The politicians and the religious leaders and the weapons scientists have been at it for a long time and they've made a thorough mess of it. I mean, we're in deep trouble. — Carl Sagan

There is something stunningly narrow about how the Anthropic Principle is phrased. Yes, only certain laws and constants of nature are consistent with our kind of life. But essentially the same laws and constants are required to make a rock. So why not talk about a Universe designed so rocks could one day come to be, and strong and weak Lithic Principles? If stones could philosophize, I imagine Lithic Principles would be at the intellectual frontiers. — Carl Sagan

Exactly the same technology can be used for good and for evil. It is as if there were a God who said to us, I set before you two ways: You can use your technology to destroy yourselves or to carry you to the planets and the stars. It's up to you — Carl Sagan

On Titan the molecules that have been raining down like manna from heaven for the last 4 billion years might still be there largely unaltered deep-frozen awaiting the chemists from Earth — Carl Sagan

There is never only ONE of anything in nature. — Carl Sagan

In a complex universe, in a society undergoing unprecedented change, how can we find the truth if we are not willing to question everything and to give a fair hearing to everything? — Carl Sagan

In exchange for freedom of inquiry, scientists are obliged to explain their work. — 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

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. — Carl Sagan

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

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

This looks very much as if the integration of the day's experience into our memory, the forging of new neural links, is either an easier or a more urgent task. As the night wears on and this function is completed, the more affecting dreams, the more bizarre
material, the fears and lusts and other powerful emotions of the
dream material emerge. — Carl Sagan

We today can recognize the antiquity of astrology in words such as disaster, which is Greek for "bad star," influenza, Italian for (astral) "influence"; mazeltov, Hebrew - and, ultimately, Babylonian - for "good constellation," or the Yiddish word shlamazel, applied to someone plagued by relentless ill-fortune, which again traces to the Babylonian astronomical lexicon. According to Pliny, there were Romans considered sideratio, "planet-struck." Planets were widely thought to be a direct cause of death. Or consider consider: it means "with the planets," evidently a prerequisite for serious reflection. — Carl Sagan

Those are some of the things that molecules do, given four billion years of evolution — 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

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

It is interesting that it is not the getting of any sort of knowledge that God has forbidden, but, specifically, the knowledge of the difference between good and evil-that is, abstract and moral judgments, which, if they reside anywhere, reside in the neocortex. — Carl Sagan

Science exacts a substantial entry fee in effort and tedium in exchange for its insights. — Carl Sagan

We invest far off places with a certain romance ... Long summers, mild winters, rich harvests, plentiful game; none of them lasts for ever. Your own life, or your bands, or even your species - might be owed to a restless few, drawn by a craving they can hardly articulate or understand, to undiscovered lands, and new worlds. — Carl Sagan

By my reckoning, I'm about 100 kilometers from Pathfinder. Technically it's called "Carl Sagan Memorial Station." But with all due respect to Carl, I can call it whatever the hell I want. I'm the King of Mars. — Andy Weir

If we know only our own side of the argument, we hardly know even that; it becomes stale, soon learned only by rote, untested, a pallid and lifeless truth. — Carl Sagan

If the general picture of an expanding universe and a Big Bang is correct, we must then confront still more difficult questions. What were conditions like at the time of the Big Bang? What happened before that? Was there a tiny universe, devoid of all matter, and then the matter suddenly created from nothing? How does that happen? 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 decide that the origin of the universe is an unanswerable question? Or, if we say that God has always existed, why not save a step and conclude that the universe has always existed? — Carl Sagan

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

If people knew how many people, especially the very rich and powerful ones, went to psychics, their jaws would drop through the floor, — Carl Sagan

Books are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil. — Carl Sagan

I do not imagine that many people in the fifteenth century ever wondered if they were living in the Italian Renaissance. — Carl Sagan

The old exhortations to nationalist fervor and jingoist pride have begun to lose their appeal. Perhaps because of rising standards of living, children are being treated better worldwide. In only a few decades, sweeping global changes have begun to move in precisely the directions needed for human survival. A new consciousness is developing which recognizes that we are one species. — Carl Sagan