Carl Sagan

“I don't want to believe. I want to know.”

“For me, the most ironic token of [the first human moon landing] is the plaque signed by President Richard M. Nixon that Apollo 11 took to the moon. It reads: "We came in peace for all Mankind." As the United States was dropping 7 ½ megatons of conventional explosives on small nations in Southeast Asia, we congratulated ourselves on our humanity. We would harm no one on a lifeless rock.”

“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.”

“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”

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

“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.”

“She had studied the universe all her life, but had overlooked its clearest message: For small creatures such as we the vastness is bearable only through love.”

“Science cuts two ways, of course; its products can be used for both good and evil. But there's no turning back from science.”

“We all have a thirst for wonder. It's a deeply human quality. Science and religion are both bound up with it. What I'm saying is, you don't have to make stories up, you don't have to exaggerate. There's wonder and awe enough in the real world. Nature's a lot better at inventing wonders than we are.”

“Understanding is a kind of ecstasy”

“It seems to me what is called for is an exquisite balance between two conflicting needs: the most skeptical scrutiny of all hypotheses that are served up to us and at the same time a great openness to new ideas...If you are only skeptical, then no new ideas make it through to you … On the other hand, if you are open to the point of gullibility and have not an ounce of skeptical sense in you, then you cannot distinguish the useful ideas from the worthless ones.”

“Any faith that admires truth, that strives to know God, must be brave enough to accommodate the universe.”

“We succeeded in taking that picture from deep space, and, if you look at it, you see a dot. That’s here. That’s home. That’s us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every 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.”

“Long ago, when an early galaxy began to pour light out into the surrounding darkness, no witness could have known that billions of years later some remote clumps of rock and metal, ice and organic molecules would fall together to make place called Earth; or that life would arise and thinking beings evolve who would one day capture a little of that galactic light, and try to puzzle out what had sent it on its way. And after the earth dies, some 5 billion years from now, after it's burned to a crisp, or even swallowed by the Sun, there will be other worlds and stars and galaxies coming into being -- and they will know nothing of a place once called Earth.”

“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.”

“A new concept of god: “something not very different from the sum total of the physical laws of the universe; that is, gravitation plus quantum mechanics plus grand unified field theories plus a few other things equaled god. And by that all they meant was that here were a set of exquisitely powerful physical principles that seemed to explain a great deal that was otherwise inexplicable about the universe. Laws of nature…that apply not just locally, not just in Glasgow, but far beyond: Edinburgh, Moscow…Mars…the center of the Milky Way, and out by the most distant quarters known. That the same laws of physics apply everywhere is quite remarkable. Certainly that represents a power greater than any of us.”

“El escepticismo tiene por función ser peligroso. Es un desafío a las instituciones establecidas. Si enseñamos a todo el mundo, incluyendo por ejemplo a los estudiantes de educación secundaria, unos hábitos de pensamiento escéptico, probablemente no limitarán su escepticismo a los ovnis, los anuncios de aspirinas y los profetas canalizados de 35.000 años. Quizá empezarán a hacer preguntas importantes sobre las instituciones económicas, sociales, políticas o religiosas. Quizá desafiarán las opiniones de los que están en el poder. ¿Dónde estaremos entonces?”

“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.”

“There are huge advertising budgets only when there's no difference between the products. If the products really were different, people would buy the one that's better. Advertising teaches people not to trust their judgment. Advertising teaches people to be stupid.”

“We are the local embodiment of a Cosmos grown to self-awareness. 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.”

“Books are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil.”

“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.”

“To make a contented slave,’ [Frederick] Bailey later wrote, ‘it is necessary to make a thoughtless one. It is necessary to darken his moral and mental vision, and, as far as possible, to annihilate the power of reason.’ This is why the slaveholders must control what slaves hear and see and think. This is why reading and critical thinking are dangerous, indeed subversive, in an unjust society.”

“There are naive questions, tedious questions, ill-phrased questions, questions put after inadequate self-criticism. But every question is a cry to understand the world. There is no such thing as a dumb question.”

“I find many adults are put off when young children pose scientific questions. Why is the Moon round? the children ask. Why is grass green? What is a dream? How deep can you dig a hole? When is the world’s birthday? Why do we have toes? Too many teachers and parents answer with irritation or ridicule, or quickly move on to something else: ‘What did you expect the Moon to be, square?’ Children soon recognize that somehow this kind of question annoys the grown-ups. A few more experiences like it, and another child has been lost to science. Why adults should pretend to omniscience before 6-year-olds, I can’t for the life of me understand. What’s wrong with admitting that we don’t know something? Is our self-esteem so fragile?”

“Every now and then, I’m lucky enough to teach a kindergarten or first-grade class. Many of these children are natural-born scientists - although heavy on the wonder side and light on scepticism. They’re curious, intellectually vigorous. Provocative and insightful questions bubble out of them. They exhibit enormous enthusiasm. I’m asked follow-up questions. They’ve never heard of the notion of a ‘dumb question’.But when I talk to high school seniors, I find something different. They memorize ‘facts’. By and large, though, the joy of discovery, the life behind those facts, has gone out of them. They’ve lost much of the wonder, and gained very little scepticism. They’re worried about asking ‘dumb’ questions; they’re willing to accept inadequate answers; they don’t pose follow-up questions; the room is awash with sidelong glances to judge, second-by-second, the approval of their peers.”

“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.”

“The ancient Ionians were the first we know of to argue systematically that laws and forces of Nature, rather than gods, are responsible for the order and even the existence of the world.”

“It's hard to kill a creature once it lets you see its consciousness.”

“Both scepticism and wonder are skills that need honing and practice. Their harmonious marriage within the mind of every schoolchild ought to be a principal goal of public education. I’d love to see such a domestic felicity portrayed in the media, television especially: a community of people really working the mix - full of wonder, generously open to every notion, dismissing nothing except for good reason, but at the same time, and as second nature, demanding stringent standards of evidence; and these standards applied with at least as much rigour to what they hold dear as to what they are tempted to reject with impunity.”

“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.”

“And yet, the chief deficiency I see in the sceptical movement is in its polarization: Us v. Them - the sense that we have a monopoly on the truth; that those other people who believe in all these stupid doctrines are morons; that if you’re sensible, you’ll listen to us; and if not, you’re beyond redemption. This is unconstructive. It does not get the message across. It condemns the sceptics to permanent minority status; whereas, a compassionate approach that from the beginning acknowledges the human roots of pseudoscience and superstition might be much more widely accepted.”

“If we offer too much silent assent about mysticism and superstition - even when it seems to be doing a little good - we abet a general climate in which scepticism is considered impolite, science tiresome, and rigorous thinking somehow stuffy and inappropriate. Figuring out a prudent balance takes wisdom.”

“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.”

“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.”

“A scientist places an ad in a Paris newspaper offering a free horoscope. He receives about 150 replies, each, as requested, detailing a place and time of birth. Every respondent is then sent the identical horoscope, along with a questionnaire asking how accurate the horoscope had been. Ninety-four per cent of the respondents (and 90 per cent of their families and friends) reply that they were at least recognizable in the horoscope. However, the horoscope was drawn up for a French serial killer. If an astrologer can get this far without even meeting his subjects, think how well someone sensitive to human nuances and not overly scrupulous might do.”

“Seances occur only in darkened rooms, where the ghostly visitors can be seen dimly at best. If we turn up the lights a little, so we have a chance to see what’s going on, the spirits vanish. They’re shy, we’re told, and some of us believe it. In twentieth-century parapsychology laboratories, there is the ‘observer effect’: those described as gifted psychics find that their powers diminish markedly whenever sceptics arrive, and disappear altogether in the presence of a conjuror as skilled as James Randi. What they need is darkness and gullibility.”

“A faith-healer may or may not start out with fraud in mind. But to his amazement, his patients actually seem to be improving. Their emotions are genuine, their gratitude heart-felt. When the healer is criticized, such people rush to his defence. Several elderly attendees of the channelling at the Sydney Opera House were incensed after the Sixty Minutes expose: ‘Never mind what they say,’ they told Alvarez, ‘we believe in you`. These successes may be enough to convince many charlatans, no matter how cynical they were at the beginning, that they actually have mystical powers. Maybe they’re not successful every time. The powers come and go, they tell themselves. They have to cover the down time. If they must cheat a little now and then, it serves a higher purpose, they tell themselves. Their spiel is consumer-tested. It works.”

“After hearing much from his patients about alleged faith-healing, a Minnesota physician named William Nolen spent a year and a half trying to track down the most striking cases. Was there clear medical evidence that the disease was really present before the ‘cure’? If so, had the disease actually disappeared after the cure, or did we just have the healer’s or the patient’s say-so? He uncovered many cases of fraud, including the first exposure in America of ‘psychic surgery’. But he found not one instance of cure of any serious organic (non-psychogenic) disease. There were no cases where gallstones or rheumatoid arthritis, say, were cured, much less cancer or cardiovascular disease. When a child’s spleen is ruptured, Nolen noted, perform a simple surgical operation and the child is completely better. But take that child to a faith-healer and she’s dead in a day.”

“When conventional medicine fails, when we must confront pain and death, of course we are open to other prospects for hope.And, after all, some illnesses are psychogenic. Many can be at least ameliorated by a positive cast of mind. Placebos are dummy drugs, often sugar pills. Drug companies routinely compare the effectiveness of their drugs against placebos given to patients with the same disease who had no way to tell the difference between the drug and the placebo. Placebos can be astonishingly effective, especially for colds, anxiety, depression, pain, and symptoms that are plausibly generated by the mind. Conceivably, endorphins -the small brain proteins with morphine-like effects - can be elicited by belief. A placebo works only if the patient believes it’s an effective medicine. Within strict limits, hope, it seems, can be transformed into biochemistry.”

“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.”

“Gullibility kills.”

“A statement: children who watch violent TV programmes tend to be more violent when they grow up. But did the TV cause the violence, or do violent children preferentially enjoy watching violent programmes? Very likely both are true. Commercial defenders of TV violence argue that anyone can distinguish between television and reality. But Saturday morning children’s programmes now average 25 acts of violence per hour. At the very least this desensitizes young children to aggression and random cruelty. And if impressionable adults can have false memories implanted in their brains, what are we implanting in our children when we expose them to some 100,000 acts of violence before they graduate from elementary school?”

“We are all stardust”

“Arguments from authority carry little weight – authorities have made mistakes in the past. They will do so again in the future. Perhaps a better way to say it is that in science there are no authorities; at most, there are experts.”

“A deception arises, sometimes innocently but collaboratively, sometimes with cynical premeditation. Usually the victim is caught up in a powerful emotion - wonder, fear, greed, grief. Credulous acceptance of baloney can cost you money; that’s what P.T. Barnum meant when he said, “There’s a sucker born every minute’. But it can be much more dangerous than that, and when governments and societies lose the capacity for critical thinking, the results can be catastrophic, however sympathetic we may be to those who have bought the baloney.”

“Paid product endorsements, especially by real or purported experts, constitute a steady rainfall of deception. They betray contempt for the intelligence of their customers. They introduce an insidious corruption of popular attitudes about scientific objectivity.”

“I grew up in Brooklyn, New York.. a city neighborhood that included houses, lampposts, walls, and bushes. But with an early bedtime in the winter, I could look out my window and see the stars, and the stars were not like anything else in my neighborhood. [At age 5] I didn’t know what they were. [At age 9] my mother … said to me, “You have a library card now, and you know how to read. Take the streetcar to the library and get a book on stars.” … I stepped up to the big librarian and asked for a book on stars. … I sat down and found out the answer, which was something really stunning. I found out that the stars are glowing balls of gas. I also found out that the Sun is a star but really close and that the stars are all suns except really far away I didn’t know any physics or mathematics at that time, but I could imagine how far you’d have to move the Sun away from us till it was only as bright as a star. It was in that library, reading that book, that the scale of the universe opened up to me. There was something beautiful about it. At that young age, I already knew that I’d be very happy if I could devote my life to finding out more about the stars and the planets that go around them. And it’s been my great good fortune to do just that.”

“Our perceptions are fallible. We sometimes see what isn't there. We are prey to optical illusions. Occasionally we hallucinate. We are error-prone.”

“In exact parallel to regressing people so they supposedly retrieve forgotten memories of ‘past lives’, Frankel notes that therapists can as readily progress people under hypnosis so they can ‘remember’ their futures. This elicits the same emotive intensity as in regression or in Mack’s abductee hypnosis. ‘These people are not out to deceive the therapist. They deceive themselves,’ Frankel says. They cannot distinguish their confabulations from their experiences.”