Carl Sagan Science Quotes & Sayings

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

We inhabit a universe where atoms are made in the centers of stars; where each second a thousand suns are born; where life is sparked by sunlight and lightning in the airs and waters of youthful planets; where the raw material for biological evolution is sometimes made by the explosion of a star halfway across the Milky Way; where a thing as beautiful as a galaxy is formed a hundred billion times - a Cosmos of quasars and quarks, snowflakes and fireflies, where there may be black holes and other universe and extraterrestrial civilizations whose radio messages are at this moment reaching the Earth. How pallid by comparison are the pretensions of superstition and pseudoscience; how important it is for us to pursue and understand science, that characteristically human endeavor. — Carl Sagan

Science is an ongoing process. It never ends. There is no single ultimate truth to be achieved, after which all the scientists can retire. And because this is so, the world is far more interesting, both for the scientists and for the millions of people in every nation who, while not professional scientists, are deeply interested in the methods and findings of science. — Carl Sagan

You squeeze the eyedropper, and a drop of pond water drips out onto the microscope stage. You look at the projected image. The drop is full of life - strange beings swimming, crawling, tumbling; high dramas of pursuit and escape, triumph and tragedy. This is a world populated by beings far more exotic than in any science fiction movie ... — Carl Sagan

Cutting off fundamental, curiosity-driven science is like eating the seed corn. We may have a little more to eat next winter but what will we plant so we and our children will have enough to get through the winters to come? — 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

My main reason for scepticism about the Huxley/Sagan theory is that the human brain is demonstrably eager to see faces in random patterns, as we know from scientific evidence, on top of the numerous legends about faces of Jesus, or the Virgin Mary, or Mother Teresa, being seen on slices of toast, or pizzas, or patches of damp on a wall. This eagerness is enhanced if the pattern departs from randomness in the specific direction of being symmetrical. — Richard Dawkins

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

Had Jupiter been several dozen times more massive, the matter in its interior would have undergone thermonuclear reactions, and Jupiter would have begun to shine by its own light. The largest planet is a star that failed. — 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

We are all star stuff. — Carl Sagan

All civilizations become either spacefaring or extinct. — 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

In the 1970s, we had Carl Sagan, and he was so suave with his turtleneck and his tweed jacket. And he was, you know, he made science look cool. And in punk rock, we haven't had that. We haven't had the Carl Sagan of punk. — Greg Graffin

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

When Kepler found his long-cherished belief did not agree with the most precise observation, he accepted the uncomfortable fact. He preferred the hard truth to his dearest illusions, that is the heart of science. — 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

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

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

While ritual, emotion and reasoning are all significant aspects of human nature, the most nearly unique human characteristic is the ability to associate abstractly and to reason. Curiosity and the urge to solve problems are the emotional hallmarks of our species; and the most characteristically human activities are mathematics, science, technology, music and the arts
a somewhat broader range of subjects than is usually included under the "humanities." Indeed, in its common usage this very word seems to reflect a peculiar narrowness of vision about what is human. Mathematics is as much a "humanity" as poetry. — Carl Sagan

Especially where the implications of what we think we are seeing seem to be profound, we may not exercise adequate self-discipline and self-criticism. — Carl Sagan

Why do we put up with it? Do we like to be criticized? No, no scientist enjoys it. Every scientist feels a proprietary affection for his or her ideas and findings. Even so, you don't reply to critics, Wait a minute; this is a really good idea; I'm very fond of it; it's done you no harm; please leave it alone. Instead, the hard but just rule is that if the ideas don't work, you must throw them away. — Carl Sagan

There is much that science doesn't understand, many mysteries still to be resolved. In a Universe tens of billions of light-years across and some ten or fifteen billion years old, this may be the case forever. We are constantly stumbling on new surprises — Carl Sagan

When we look up at night and view the stars, everything we see is shinning because of distant nuclear fusion. — Carl Sagan

Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves. — Carl Sagan

Consider again that dot [Earth]. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there - on a mote of dust suspended in a sunbeam. — Carl Sagan

Whatever their neurological and molecular antecedents, hallucinations feel real. They are sought out in many cultures and considered a sign of spiritual enlightenment. — Carl Sagan

If we could travel into the past, it's mind-boggling what would be possible. For one thing, history would become an experimental science, which it certainly isn't today. The possible insights into our own past and nature and origins would be dazzling. For another, we would be facing the deep paradoxes of interfering with the scheme of causality that has led to our own time and ourselves. I have no idea whether it's possible, but it's certainly worth exploring. — Carl Sagan

[Science] works. It is not perfect. It can be misused. It is only a tool. But it is by far the best tool we have, self-correcting, ongoing, applicable to everything. It has two rules. First: there are no sacred truths; all assumptions must be critically examined; arguments from authority are
worthless. Second: whatever is inconsistent with the facts must be discarded or revised. We must understand the Cosmos as it is and not confuse how it is with how we wish it to be. The obvious is sometimes false; the unexpected is sometimes true. — Carl Sagan

I don't think science is hard to teach because humans aren't ready for it, or because it arose only through a fluke, or because, by and large, we don't have the brainpower to grapple with it. Instead, the enormous zest for science that I see in first-graders and the lesson from the remnant hunter-gatherers both speak eloquently: A proclivity for science is embedded deeply within us, in all times, places, and cultures. It has been the means for our survival. It is our birthright. When, through indifference, inattention, incompetence, or fear of skepticism, we discourage children from science, we are disenfranchising them, taking from them the tools needed to manage their future. — Carl Sagan

If you're only sceptical, then no new ideas make it through to you. You never learn anything. You become a crochety misanthrope convinced that nonsense is ruling the world. (There is, of course, much data to support you.) Since major discoveries in the borderlines of science are rare, experience will tend to confirm your grumpiness. But every now and then a new idea turns out to be on the mark, valid and wonderful. If you're too resolutely and uncompromisingly sceptical, you're going to miss (or resent) the transforming discoveries in science, and either way you will be obstructing understanding and progress. Mere scepticism is not enough. — 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

Ours is the first generation that has grown up with science-fiction ideas. — Carl Sagan

I reject the notion that science is by its nature secretive. Its culture and ethos are, and for very good reason, collective, collaborative, and communicative. — Carl Sagan

The fossil record implies trial and error, the inability to anticipate the future, features inconsistent with a Great Designer (though not a Designer of a more remote and indirect temperament.) — Carl Sagan

If the press descended, the science would surely suffer. — Carl Sagan

The lifetime of a human being is measured by decades, the lifetime of the Sun is a hundred million times longer. Compared to a star, we are like mayflies, fleeting ephemeral creatures who live out their lives in the course of a single day. — Carl Sagan

Pseudoscience speaks to powerful emotional needs that science often leaves unfulfilled. It caters to fantasies about personal powers we lack and long for. — Carl Sagan

You can get into a habit of thought in which you enjoy making fun of all those other people who don't see things as clearly as you do. We have to guard carefully against it. — Carl Sagan

We are the only species on the planet, so far as we know, to have invented a communal memory stored neither in our genes nor in our brains. The warehouse of this memory is called the library — Carl Sagan

All over the world there are enormous numbers of smart, even gifted, people who harbor a passion for science. But that passion is unrequited. Surveys suggest that some 95 percent of Americans are "scientifically illiterate." That's just the same fraction as those African Americans, almost all of them slaves, who were illiterate just before the Civil War - when severe penalties were in force for anyone who taught a slave to read. Of course there's a degree of arbitrariness about any determination of illiteracy, whether it applies to language or to science. But anything like 95 percent illiteracy is extremely serious. — Carl Sagan

When you're in love, you want to tell the world. My lifelong love affair with science — 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

We need to reduce military budgets; raise living standards; engender respect for learning; support science, scholarship, invention, and industry; promote free inquiry; reduce domestic coercion; involve the workers more in managerial decisions; and promote genuine respect and understanding derived from an acknowledgement of our common humanity and our common jeopardy. — 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

The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge, and there's no place for it in the endeavor of science. We do not know beforehand where fundamental insights will arise from about our mysterious and lovely solar system. The history of our study of our solar system shows us clearly that accepted and conventional ideas are often wrong, and that fundamental insights can arise from the most unexpected sources. — Carl Sagan

The notion that science and spirituality are somehow mutually exclusive does a disservice to both. — Carl Sagan

No question; language can free us of feeling, or almost. Maybe that's one of its functions - so we can understand the world without becoming entirely overwhelmed by it. — Carl Sagan

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

We grow up in isolation. Only slowly do we teach ourselves the Cosmos. — Carl Sagan

[When a religious couple wrote to Sagan about fulfilled prophecies, he wrote back in May 1996:]

If 'fulfilled prophecy' is your criterion, why do you not believe in materialistic science, which has an unparalleled record of fulfilled prophecy? Consider, for example, eclipses. — Carl Sagan

Any faith that admires truth, that strives to know God, must be brave enough to accommodate the universe. — Carl Sagan

We are an intelligent species and the use of our intelligence quite properly gives us pleasure. In this respect the brain is like a muscle. When we think well, we feel good. Understanding is a kind of ecstasy. — Carl Sagan

A new consciousness is developing which sees the earth as a single organism and recognizes that an organism at war with itself is doomed. We are one planet. One of the great revelations of the age of space exploration is the image of the earth finite and lonely, somehow vulnerable, bearing the entire human species through the oceans of space and time. — Carl Sagan

Science is generated by and devoted to free inquiry: the idea that any hypothesis, no matter how strange, deserves to be considered on its merits. 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. We do not know in advance who will discover fundamental new insights. — Carl Sagan

The same few dozen organic molecules are used over and over again in biology for the widest variety of functions. — 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Faith is clearly not enough for many people. They crave hard evidence, scientific proof. They long for the scientific seal of approval, but are unwilling to put up with the rigorous standards of evidence that impart credibility to that seal. What a relief it would be: doubt reliably abolished! Then the irksome burden of looking after ourselves would be lifted. We're worried - and for good reason - about what it means for the human future if we have only ourselves to rely upon. — 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

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

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

Interviewer: Didn't Sagan want to believe?
Druyan: he didn't want to believe. he wanted to know. — Ann Druyan

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

If you want to save your child from polio, you can pray or you can inoculate ... Choose science. — Carl Sagan

The theologian Meric Casaubon argued - in his 1668 book, Of Credulity and Incredulity - that witches must exist because, after all, everyone believes in them. Anything that a large number of people believe must be true. — Carl Sagan

As my old professor Carl Sagan said so often, 'When you're in love, you want to tell the world.' And I base my beliefs on the information and the process that we call science. It fills me with joy to make discoveries every day of things I've never seen before. It fills me with joy to know that we can pursue these answers. It is an astonishing thing that we are - you and I are one of the ways the universe knows itself. — Bill Nye

The method of science, as stodgy and grumpy as it may seem, is far more important than the findings of science. — Carl Sagan

Meanwhile the Cosmos is rich beyond measure: the total number of stars in the universe is greater than all the grains of sand on all the beaches of the planet Earth. — Carl Sagan

Black holes collect problems faster than they collect matter. — Carl Sagan

A religion old or new, that stressed the magnificence of the universe as revealed by modern science, might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths. Sooner or later such a religion will emerge. — Carl Sagan

Science is a way to not fool ourselves. — Carl Sagan

It may be that there are kernels of truth in a few of these doctrines, but their widespread acceptance
betokens a lack of intellectual rigor, an absence of skepticism, a need to replace experiments by desires. — Carl Sagan

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

Science gropes and staggers toward improved understanding. — Carl Sagan

If you are only skeptical, then no new ideas make it through to you. — Carl Sagan

Then science came along and taught us that we are not the measure of all things, that there are wonders unimagined, that the Universe is not obliged to conform to what we consider comfortable or plausible. We have learned something about the idiosyncratic nature of our common sense. Science has carried human self-consciousness to a higher level. This is surely a rite of passage, a step towards maturity. — Carl Sagan

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