Carl Sagan

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

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

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

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

"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."

"With insufficient data it is easy to go wrong."

"Our intelligence and our technology have given us the power to affect the climate. How will we use this power? Are we willing to tolerate ignorance and complacency in matters that affect the entire human family? Do we value short-term advantages above the welfare of the Earth? Or will we think on longer time scales, with concern for our children and our grandchildren, to understand and protect the complex life-support systems of our planet? The Earth is a tiny and fragile world. It needs to be cherished."

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

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

"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."

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

"For as long as there been humans we have searched for our place in the cosmos. Where are we? Who are we? We find that we live on an insignificant planet of a hum-drum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people. This perspective is a courageous continuation of our penchant for constructing and testing mental models of the skies; the Sun as a red-hot stone, the stars as a celestial flame, the Galaxy as the backbone of night."

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

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

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

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

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

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

"Matter is composed chiefly of nothing."

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

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

"Nobody listens to mathematicians."

"The neurochemistry of the brain is astonishingly busy, the circuitry of a machine more wonderful than any devised by humans. But there is no evidence that its functioning is due to anything more than the 1014 neural connections that build an elegant architecture of consciousness."

"Books permit us to voyage through time, to tap the wisdom of our ancestors. The library connects us with the insights and knowledge, painfully extracted from Nature, of the greatest minds that ever were, with the best teachers, drawn from the entire planet and from all of our history, to instruct us without tiring, and to inspire us to make our own contribution to the collective knowledge of the human species. Public libraries depend on voluntary contributions. I think the health of our civilization, the depth of our awareness about the underpinnings of our culture and our concern for the future can all be tested by how well we support our libraries."

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

"The choice is with us still, but the civilization now in jeopardy is all humanity. As the ancient myth makers knew, we are 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 and 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 immensity of the Cosmos, an inescapable perspective awaits us. There are not yet any obvious signs of extraterrestrial intelligence and this makes us wonder whether civilizations like ours always rush implacably, headlong, toward self-destruction. National boundaries are not evident when we view the Earth from space. Fanatical ethnic or religious or national chauvinisms are a little difficult to maintain when we see our planet as a fragile blue crescent fading to become an inconspicuous point of light against the bastion and citadel of the stars. Travel is broadening."

"The chiliasts made an atheist out of me."

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

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

"There is no other species on the Earth that does science. It is, so far, entirely a human invention, evolved by natural selection in the cerebral cortex for one simple reason: it 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."

"Human history can be viewed as a slowly dawning awareness that we are members of a larger group. Initially our loyalties were to ourselves and our immediate family, next, to bands of wandering hunter-gatherers, then to tribes, small settlements, city-states, nations. We have broadened the circle of those we love. We have now organized what are modestly described as super-powers, which include groups of people from divergent ethnic and cultural backgrounds working in some sense together — surely a humanizing and character building experience. If we are to survive, our loyalties must be broadened further, to include the whole human community, the entire planet Earth. Many of those who run the nations will find this idea unpleasant. They will fear the loss of power. We will hear much about treason and disloyalty. Rich nation-states will have to share their wealth with poor ones. But the choice, as H. G. Wells once said in a different context, is clearly the universe or nothing."

"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."

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

"The Hindu religion is the only one of the world’s great faiths dedicated to the idea that the cosmos itself undergoes an immense and indeed an infinite number of deaths and rebirths. It is the only religion in which the time scales correspond […] to those of modern scientific cosmology."

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

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

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

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

"If the press descended, the science would surely suffer."

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

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

"Do we, holding that the gods exist, deceive ourselves with insubstantial dreams and lies, while random careless chance and change alone control the world?"

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

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

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

"Jingoistic rhetoric and puerile self-congratulatory nationalism."

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

"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."

"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."