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."

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

"The chiliasts made an atheist out of me."

"You see, the religious people — most of them — really think this planet is an experiment. That's what their beliefs come down to. Some god or other is always fixing and poking, messing around with tradesmen's wives, giving tablets on mountains, commanding you to mutilate your children, telling people what words they can say and what words they can't say, making people feel guilty about enjoying themselves, and like that. Why can't the gods leave well enough alone? All this intervention speaks of incompetence. If God didn't want Lot's wife to look back, why didn't he make her obedient, so she'd do what her husband told her? Or if he hadn't made Lot such a shithead, maybe she would've listened to him more. If God is omnipotent and omniscient, why didn't he start the universe out in the first place so it would come out the way he wants? Why's he constantly repairing and complaining? No, there's one thing the Bible makes clear: The biblical God is a sloppy manufacturer. He's not good at design, he's not good at execution. He'd be out of business if there was any competition."

"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."

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

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

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

"That it will never come again Is what makes life so sweet."

"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."

"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."

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

"The universe was made on purpose, the circle said. In whatever galaxy you happen to find yourself, you take the circumference of a circle, divide it by its diameter, measure closely enough, and uncover a miracle — another circle, drawn kilometers downstream of the decimal point. There would be richer messages farther in. It doesn't matter what you look like, or what you're made of, or where you come from. As long as you live in this universe, and have a modest talent for mathematics, sooner or later you'll find it. It's already here. It's inside everything. You don't have to leave your planet to find it. In the fabric of space and in the nature of matter, as in a great work of art, there is, written small, the artist's signature. Standing over humans, gods, and demons, subsuming Caretakers and Tunnel builders, there is an intelligence that antedates the universe."

"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."

"We wish to pursue the truth no matter where it leads — but to find the truth, we need imagination and skepticism both. We will not be afraid to speculate, but we will be careful to distinguish speculation from fact. 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."

"The cosmic calendar compresses the local history of the universe into a single year. If the universe began on January 1st it was not until May that the Milky Way formed. Other planetary systems may have appeared in June, July and August, but our Sun and Earth not until mid-September. Life arose soon after."

"We humans appear on the cosmic calendar so recently that our recorded history occupies only the last few seconds of the last minute of December 31st."

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

"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."

"..every cell is a triumph of natural selection. And we're made of trillions of cells. We are, each of us, a multitude. Within us is a little universe."

"The desire to be connected with the cosmos reflects a profound reality for we are connected. Not in the trivial ways that the pseudo-science of astrology promises but in the deepest ways."

"If we lived on a planet where nothing ever changed there wouldn't be much to do. There'd be nothing to figure out. There'd be no impetus for science. And if we lived in an unpredictable world where things changed in random or complex ways we wouldn't be able to figure things out. And again, there'd be no such thing as science. But 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. If I throw a stick up in the air it always falls down. If the sun sets in the west it always rises again the next morning in the east. And so, it's possible to figure things out. We can do science, and with it we can improve our lives."

"If such things were fated by the stars then perhaps there were hidden patterns underlying the unpredictable chaos of daily life. Patterns as constant as the stars. But how could you discover them? Where would you begin? If the world and everything in it was crafted by God then shouldn't you begin with a careful study of physical reality? Was not all of creation an expression of the harmonies in the mind of God? The book of nature had waited 1,500 years for a reader."

"As a boy Kepler had been captured by a vision of cosmic splendour, a harmony of the worlds which he sought so tirelessly all his life. Harmony in this world eluded him. His three laws of planetary motion represent, we now know, a real harmony of the worlds, but to Kepler they were only incidental to his quest for a cosmic system based on the Perfect Solids, a system which, it turns out, existed only in his mind. Yet from his work, we have found that scientific laws pervade all of nature, that the same rules apply on Earth as in the skies, that we can find a resonance, a harmony, between the way we think and the way the world works. When he found that his long cherished beliefs did not agree with the most precise observations, he accepted the uncomfortable facts, he preferred the hard truth to his dearest illusions. That is the heart of science."

"There are many hypotheses in science that are wrong. That's perfectly all right; it's the aperture to finding out what's right. Science is a self-correcting process. To be accepted, new ideas must survive the most rigorous standards of evidence and scrutiny. The worst aspect of the Velikovsky affair is not that many of his ideas were wrong or silly or in gross contradiction to the facts; rather, the worst aspect is that some scientists attempted to suppress Velikovsky's ideas. The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge and there is 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, and the history of our study of the solar system shows clearly that accepted and conventional ideas are often wrong and that fundamental insights can arise from the most unexpected sources."

"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."

"A tiny blue dot set in a sunbeam. Here it is. That's where we live. That's home. We humans are one species and this is our world. It is our responsibility to cherish it. Of all the worlds in our solar system, the only one so far as we know, graced by life."

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

"There can be an infinite number of polygons, but only five regular solids. Four of the solids were associated with earth, fire, air and water. The cube for example represented earth. These four elements, they thought, make up terrestrial matter. So the fifth solid they mystically associated with the Cosmos. Perhaps it was the substance of the heavens. This fifth solid was called the dodecahedron. Its faces are pentagons, twelve of them. Knowledge of the dodecahedron was considered too dangerous for the public. Ordinary people were to be kept ignorant of the dodecahedron. In love with whole numbers, the Pythagoreans believed that all things could be derived from them. Certainly all other numbers. So a crisis in doctrine occurred when they discovered that the square root of two was irrational. That is: the square root of two could not be represented as the ratio of two whole numbers, no matter how big they were. "Irrational" originally meant only that. That you can't express a number as a ratio. But for the Pythagoreans it came to mean something else, something threatening, a hint that their world view might not make sense, the other meaning of "irrational"."

"Instead of wanting everyone to share and know of their discoveries the Pythagoreans suppressed the square root of two and the dodecahedron. The outside world was not to know. The Pythagoreans had discovered, in the mathematical underpinnings of nature, one of the two most powerful scientific tools, the other of course is experiment, but instead of using their insight to advance the collective voyage of human discovery they made of it little more than the hocus-pocus of a mystery cult. Science and mathematics were to be removed from the hands of the merchants and the artisans."

"But why had science lost its way in the first place? What appeal could these teachings of Pythagoras and Plato have had for their contemporaries? They provided, I believe, an intellectually respectable justification for a corrupt social order. The mercantile tradition that had led to Ionian science also led to a slave economy. You could get richer if you owned a lot of slaves. Athens in the time of Plato and Aristotle had a vast slave population. All that brave Athenian talk about democracy applied only to a privileged few."

"We are star stuff, which has taken its destiny into its own hands. The loom of time and space works the most astonishing transformations of matter. Our own planet is only a tiny part of the vast cosmic tapestry, a starry fabric of worlds yet untold. Those worlds in space are as countless as all the grains of sand on all the beaches of the earth. Each of those worlds is as real as ours. In every one of them there's a succession of incidents, events, occurrences, which influence its future. Countless worlds, numberless moments, an immensity of space and time, and our small planet at this moment — here we face a critical branch point in history. What we do with our world, right now will propagate down through the centuries and powerfully affect the destiny of our descendants. It is well within our power to destroy our civilization and perhaps our species as well. If we capitulate a superstition or greed or stupidity, we can plunge our world into a darkness deeper than the time between the collapse of classical civilization and the Italian Renaissance. But we are also capable of using our compassion and our intelligence, our technology and our wealth, to make an abundant and meaningful life for every inhabitant of this planet, to enhance enormously our understanding of the universe and to carry us to the stars."

"But we don't yet know whether the Universe is open or closed. More than that, there are a few astronomers who doubt that the redshift of distant galaxies is due to the doppler effect, who are skeptical of the expanding Universe and the Big Bang. Perhaps our descendants will regard our present ignorance with as much sympathy as we feel to the ancients for not knowing the Earth went around the Sun. If the general picture, however, of a Big Bang followed by an expanding Universe is correct, what happened before that? Was the Universe devoid of all matter and then the matter suddenly somehow created, how did that happen? In many cultures, the customary answer is that a God or Gods created the Universe out of nothing. But if we wish to pursue this question courageously, we must of course ask the next question: where did God come from? If we decide that this is an unanswerable question, why not save a step and conclude that the origin of the Universe is an unanswerable question? Or, if we say that God always existed, why not save a step, and conclude that the Universe always existed? That there's no need for a creation, it was always here. These are not easy questions. Cosmology brings us face to face with the deepest mysteries, questions that were once treated only in religion and myth."

"What distinguishes our species is thought. The cerebral cortex is in a way a liberation. We need no longer be trapped in the genetically inherited behavior patterns of lizards and baboons: territoriality and aggression and dominance hierarchies. We are each of us largely responsible for what gets put in to our brains. For what as adults we wind up caring for and knowing about. No longer at the mercy of the reptile brain we can change ourselves. Think of the possibilities."

"What an astonishing thing a book is. It's a flat object made from a tree with flexible parts on which are imprinted lots of funny dark squiggles. But one glance at it and you're inside the mind of another person, maybe somebody dead for thousands of years. Across the millennia, an author is speaking clearly and silently inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. A book is proof that humans are capable of working magic."

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

"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."

"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."

"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."

"Unlike the La Pérouse expedition the Conquistadors sought not knowledge but Gold. They used their superior weapons to loot and murder, in their madness they obliterated a civilisation. In the name of piety, in a mockery of their religion, the Spaniards utterly destroyed a society with an Art, Astronomy and Architecture the equal of anything in Europe. We revile the Conquistadors for their cruelty and shortsightedness, for choosing death. We admire La Pérouse and the Tlingit for their courage and wisdom, for choosing life. The choice is with us still, but the civilisation now in jeopardy is all humanity. As the ancient myth makers knew we're children equally of the earth and the sky. In our tenure on this planet we've accumulated dangerous evolutionary baggage, propensities for aggression and ritual, submission to leaders, hostility to outsiders, all of which puts our survival in some doubt. But we've also acquired compassion for others, love for our children, a desire to learn from history and experience and a great soaring passionate intelligence, the clear tools for our continued survival and prosperity. 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. National boundaries are not evident when we view the Earth from space. Fanatical ethnic or religious or national identifications are a little difficult to support when we see our Earth as a fragile blue crescent fading to become an inconspicuous point of light against the bastion and the citadel of the stars. There are not yet obvious signs of extraterrestrial intelligence and this makes us wonder whether civilisations like ours rush inevitably headlong into self-destruction."

"Every thinking person fears nuclear war and every technological nation plans for it. Everyone knows it's madness, and every country has an excuse."

"Our global civilisation is clearly on the edge of failure and the most important task it faces, preserving the lives and well-being of its citizens and the future habitability of the planet. But if we're willing to live with the growing likelihood of nuclear war shouldn't we also been willing to explore vigorously every possible means to prevent nuclear war. Shouldn't we consider in every nation major changes in the traditional ways of doing things, a fundamental restructuring of economic political social and religious institutions. We've reached a point where there can be no more special interests or special cases, nuclear arms threaten every person on the Earth. Fundamental changes in society are sometimes labelled impractical or contrary to human nature, as if nuclear war were practical or as if there's only one human nature. But fundamental changes can clearly be made, we're surrounded by them. In the last two centuries abject slavery which was with us for thousands of years has almost entirely been eliminated in a stirring worldwide revolution. Women, systematically mistreated for millennia are gradually gaining the political and economic power traditionally denied them and some wars of aggression have recently been stopped or curtailed because of a revulsion felt by the people in the aggressor nations. The old appeals to racial, sexual, and religious chauvinism and to rabid nationalist fervor are beginning not to work. 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."

"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."

"Imagine how different our world would be if those discoveries had been explained and used for the benefit of everyone, if the humane perspective of Eratosthenes had been widely adopted and applied. But this was not to be. Alexandria was the greatest city the Western world had ever seen. People from all nations came here to live to trade to learn, on a given day these harbours were thronged with merchants and scholars and tourists, it's probably here that the word Cosmopolitan realised its true meaning of a citizen not just of a nation but of the Cosmos, to be a citizen of the Cosmos. Here were clearly the seeds of our modern world, but why didn't they take root and flourish why instead did the Western world slumber through a 1000 years of darkness until Columbus and Copernicus and their contemporaries rediscovered the work done here? I cannot give you a simple answer but I do know this, there is no record in the entire history of the library that any of the illustrious scholars and scientists who worked here ever seriously challenged a single political or economic or religious assumption of the society in which they lived. The permanence of the stars was questioned, the justice of slavery was not."

"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."

"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."

"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."

"Since this series' maiden voyage, the impossible has come to pass: Mighty walls that maintained insuperable ideological differences have come tumbling down; deadly enemies have embraced and begun to work together. The imperative to cherish the Earth and protect the global environment that sustains all of us has become widely accepted, and we've begun, finally, the process of reducing the obscene number of weapons of mass destruction. Perhaps we have, after all, decided to choose life. But we still have light years to go to ensure that choice. Even after the summits and the ceremonies and the treaties, there are still some 50,000 nuclear weapons in the world — and it would require the detonation of only a tiny fraction of them to produce a nuclear winter, the predicted global climatic catastrophe that would result from the smoke and the dust lifted into the atmosphere by burning cities and petroleum facilities. The world scientific community has begun to sound the alarm about the grave dangers posed by depleting the protective ozone shield and by greenhouse warming, and again we're taking some mitigating steps, but again those steps are too small and too slow. The discovery that such a thing as nuclear winter was really possible evolved out of the studies of Martian dust storms. The surface of Mars, fried by ultraviolet light, is also a reminder of why it's important to keep our ozone layer intact. The runaway greenhouse effect on Venus is a valuable reminder that we must take the increasing greenhouse effect on Earth seriously. Important lessons about our environment have come from spacecraft missions to the planets. By exploring other worlds we safeguard this one. By itself, I think this fact more than justifies the money our species has spent in sending ships to other worlds. It is our fate to live during one of the most perilous and, at the same time, one of the most hopeful chapters in human history. Our science and our technology have posed us a profound question. Will we learn to use these tools with wisdom and foresight before it's too late? Will we see our species safely through this difficult passage so that our children and grandchildren will continue the great journey of discovery still deeper into the mysteries of the Cosmos? That same rocket and nuclear and computer technology that sends our ships past the farthest known planet can also be used to destroy our global civilization. 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.”"

"For all its material advantages, the sedentary life has left us edgy, unfulfilled. Even after 400 generations in villages and cities, we haven't forgotten. The open road still softly calls, like a nearly forgotten song of childhood. We invest far-off places with a certain romance. This appeal, I suspect, has been meticulously crafted by natural selection as an essential element in our survival. Long summers, mild winters, rich harvests, plentiful game—none of them lasts forever. It is beyond our powers to predict the future. Catastrophic events have a way of sneaking up on us, of catching us unaware. Your own life, or your band's, 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. Herman Melville, in Moby Dick, spoke for wanderers in all epochs and meridians: "I am tormented with an everlasting itch for things remote. I love to sail forbidden seas…""

"Consider again that dot. 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. The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. 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. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known."