First Quote Added
April 10, 2026
Latest Quote Added
"A central lesson of science is that to understand complex issues (or even simple ones), we must try to free our minds of dogma and to guarantee the freedom to publish, to contradict, and to experiment. Arguments from authority are unacceptable. We are all fallible, even leaders. But however clear it is that criticism is necessary for progress, governments tend to resist."
"The methods and ethos of science and religion are profoundly different. Religion frequently asks us to believe without question, even (or especially) in the absence of hard evidence. Indeed, this is the central meaning of faith. Science asks us to take nothing on faith, to be wary of our penchant for self-deception, to reject anecdotal evidence. Science considers deep skepticism a prime virtue. Religion often sees it as a barrier to enlightenment. So, for centuries, there has been a conflict between the two fields—the discoveries of science challenging religious dogmas, and religion attempting to ignore or suppress the disquieting findings."
"Why is “energy independence” mentioned so often as a justification for environmentally risky nuclear power plants or offshore drilling—but so rarely to justify insulation, efficient cars, or wind and solar energy?"
"If we are to prevent this climactic danger from working its worst, we will simply all have to work together, and for a long time. The principle obstacle is, of course, inertia, resistance to change—huge, worldwide, interlocking industrial, economic, and political establishments all beholden to fossil fuels, when fossil fuels are the problem. In the United States, as the evidence for the seriousness of global warming mounts, the political will to do something about it seems to be shriveling."
"If we keep on with business as usual, the Earth will be warmed more every year; drought and floods both will be endemic; many more cities, provinces, and whole nations will be submerged beneath the waves—unless heroic worldwide engineering countermeasures are taken. In the longer run, still more dire consequences may follow, including the collapse of the West Antarctic ice sheet, its surge into the sea, a major global rise in sea level, and the inundation of almost all the coastal cities on the planet."
"It's hard to understand how “conservatives” could oppose safeguarding the environment—that all of us including conservatives and their children—depend on for our very lives. What exactly is it conservatives are conserving?"
"We are ignorant about the complex mutual dependencies of the beings on earth, and what the sequential consequences will be if we wipe out some especially vulnerable microbes on which larger organisms depend. We are tugging at a planetwide biological tapestry and do not know whether one thread only will come out in our hands, or whether the whole tapestry will unravel before us."
"Nearly all our problems are made by humans and can be solved by humans. No social convention, no political system, no economic hypothesis, no religious dogma is more important."
"The inhibitions placed on the irresponsible use of technology are weak, often half-hearted, and almost always, worldwide, subordinated to short-term national or corporate interest. We are now able, intentionally or inadvertently, to alter the global environment. Just how far along we are in working the various prophesied planetary catastrophes is still a matter of scholarly debate. But that we are able to do so is now beyond question."
"If we are not graced with an instinctive knowledge of how to make our technologized world a safe and balanced ecosystem, we must figure out how to do it. We need more scientific research and more technological restraint. It is probably too much to hope that some great Ecosystem Keeper in the sky will reach down and put right our environmental abuses. It is up to us. It should not be impossibly difficult. Birds—whose intelligence we tend to malign—know not to defile the nest. Shrimps with brains the size of lint particles know it. Algae know it. One-celled microorganisms know it. It is time for us to know it too."
"The laws of physics suffice, without supernatural intervention."
"If you know a thing only qualitatively, you know it no more than vaguely. If you know it quantitatively—grasping some numerical measure that distinguishes it from an infinite number of other possibilities—you are beginning to know it deeply. You comprehend some of its beauty and you gain access to its power in the understanding it provides. Being afraid of quantification is tantamount to disenfranchising yourself, giving up on one of the most potent prospects for understanding and changing the world."
"This doesn't mean you can picture a billion or a quintillion objects in your head—nobody can. But, with exponential notation, we can think about and calculate with such numbers. Pretty good for self-taught beings who started out with no possessions and who could number their fellows on their fingers and toes."
"I never said it. Honest. Oh, I said there are maybe 100 billion galaxies and 10 billion trillion stars. It's hard to talk about the Cosmos without using big numbers. I said “billion” many times on the Cosmos television series, which was seen by a great many people. But I never said “billions and billions.” For one thing, it's too imprecise. How many billions are “billions and billions”? A few billion? Twenty billion? A hundred billion? “Billions and billions” is pretty vague...For a while, out of childish pique, I wouldn't utter the phrase, even when asked to. But I've gotten over that. So, for the record, here goes: “Billions and billions.”"
"When we consider the founders of our nation: Jefferson, Washington, Samuel and John Adams, Madison and Monroe, Benjamin Franklin, Tom Paine and many others; we have before us a list of at least ten and maybe even dozens of great political leaders. They were well educated. Products of the European Enlightenment, they were students of history. They knew human fallibility and weakness and corruptibility. They were fluent in the English language. They wrote their own speeches. They were realistic and practical, and at the same time motivated by high principles. They were not checking the pollsters on what to think this week. They knew what to think. They were comfortable with long-term thinking, planning even further ahead than the next election. They were self-sufficient, not requiring careers as politicians or lobbyists to make a living. They were able to bring out the best in us. They were interested in and, at least two of them, fluent in science. They attempted to set a course for the United States into the far future — not so much by establishing laws as by setting limits on what kinds of laws could be passed. The Constitution and its Bill of Rights have done remarkably well, constituting, despite human weaknesses, a machine able, more often than not, to correct its own trajectory. At that time, there were only about two and a half million citizens of the United States. Today there are about a hundred times more. So if there were ten people of the caliber of Thomas Jefferson then, there ought to be 10 x 100 = 1,000 Thomas Jefferson's today. Where are they?"
"Education on the value of free speech and the other freedoms reserved by the Bill of Rights, about what happens when you don't have them, and about how to exercise and protect them, should be an essential prerequisite for being an American citizen — or indeed a citizen of any nation, the more so to the degree that such rights remain unprotected. 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."
"Books, purchasable at low cost, permit us to interrogate the past with high accuracy; to tap the wisdom of our species; to understand the point of view of others, and not just those in power; to contemplate — with the best teachers — the insights, painfully extracted from Nature, of the greatest minds that ever were, drawn from the entire planet and from all of our history. They allow people long dead to talk inside our heads. Books can accompany us everywhere. Books are patient where we are slow to understand, allow us to go over the hard parts as many times as we wish, and are never critical of our lapses. Books are key to understanding the world and participating in a democratic society."
"Perhaps one per cent of the time, someone who has an idea that smells, feels and looks indistinguishable from the usual run of pseudoscience will turn out to be right. Maybe some undiscovered reptile left over from the Cretaceous period will indeed be found in Loch Ness or the Congo Republic; or we will find artefacts of an advanced, non-human species elsewhere in the solar system. At the time of writing there are three claims in the ESP field which, in my opinion, deserve serious study: (1) that by thought alone humans can (barely) affect random number generators in computers; (2) that people under mild sensory deprivation can receive thoughts or images 'projected' at them; and (3) that young children sometimes report the details of a previous life, which upon checking turn out to be accurate and which they could not have known about in any other way than reincarnation. I pick these claims not because I think they're likely to be valid (I don't), but as examples of contentions that might be true. The last three have at least some, although still dubious, experimental support. Of course, I could be wrong."
"At the heart of science is an essential balance between two seemingly contradictory attitudes - an openness to new ideas, no matter how bizarre or counterintuitive, and the most ruthlessly skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. The collective enterprise of creative thinking and skeptical thinking, working together, keeps the field on track. Those two seemingly contradictory attitudes are, though, in some tension."
"One of the saddest lessons of history is this: If we've been bamboozled long enough, we tend to reject any evidence of the bamboozle. We're no longer interested in finding out the truth. The bamboozle has captured us. It's simply too painful to acknowledge, even to ourselves, that we've been taken. Once you give a charlatan power over you, you almost never get it back."
"Appeal to ignorance — the claim that whatever has not been proved false must be true, and vice versa (e.g. There is no compelling evidence that UFOs are not visiting the Earth; therefore UFOs exist — and there is intelligent life elsewhere in the universe. Or: There may be seventy kazillion other worlds, but not one is known to have the moral advancement of the Earth, so we're still central to the Universe.) This impatience with ambiguity can be criticized in the phrase: absence of evidence is not evidence of absence."
"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."
"I worry that, especially as the Millennium edges nearer, pseudo-science and superstition will seem year by year more tempting, the siren song of unreason more sonorous and attractive. Where have we heard it before? Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self-esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us-then, habits of thought familiar from ages past reach for the controls. The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir."
"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."
"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."
"We've arranged a global civilization in which the most crucial elements — transportation, communications, and all other industries; agriculture, medicine, education, entertainment, protecting the environment; and even the key democratic institution of voting — 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."
"I have a foreboding of an America in my children's or grandchildren's time -- when the United States is a service and information economy; when nearly all the manufacturing industries have slipped away to other countries; when awesome technological powers are in the hands of a very few, and no one representing the public interest can even grasp the issues; when the people have lost the ability to set their own agendas or knowledgeably question those in authority; when, clutching our crystals and nervously consulting our horoscopes, our critical faculties in decline, unable to distinguish between what feels good and what's true, we slide, almost without noticing, back into superstition and darkness."
"For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring."
"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?"
"Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history."
"If we crave some cosmic purpose, then let us find ourselves a worthy goal."
"Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home."
"The vast distances that separate the stars are providential. Beings and worlds are quarantined from one another. The quarantine is lifted only for those with sufficient self-knowledge and judgement to have safely traveled from star to star."
"Imagine we could accelerate continuously at 1 g — what we're comfortable with on good old terra firma — to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars."
"Since, in the long run, every planetary society will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring — not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive."
"A scientific colleague tells me about a recent trip to the New Guinea highlands where she visited a stone age culture hardly contacted by Western civilization. They were ignorant of wristwatches, soft drinks, and frozen food. But they knew about Apollo 11. They knew that humans had walked on the Moon. They knew the names of Armstrong and Aldrin and Collins. They wanted to know who was visiting the Moon these days."
"Those who are skeptical about carbon dioxide greenhouse warming might profitably note the massive greenhouse effect on Venus. No one proposes that Venus's greenhouse effect derives from imprudent Venusians who burned too much coal, drove fuel-inefficient autos, and cut down their forests. My point is different. The climatological history of our planetary neighbor, an otherwise Earthlike planet on which the surface became hot enough to melt tin or lead, is worth considering — especially by those who say that the increasing greenhouse effect on Earth will be self-correcting, that we don't really have to worry about it, or (you can see this in the publications of some groups that call themselves conservative) that the greenhouse effect is a "hoax"."
"It is sometimes said that scientists are unromantic, that their passion to figure out robs the world of beauty and mystery. But is it not stirring to understand how the world actually works — that white light is made of colors, that color is the way we perceive the wavelengths of light, that transparent air reflects light, that in so doing it discriminates among the waves, and that the sky is blue for the same reason that the sunset is red? It does no harm to the romance of the sunset to know a little bit about it."
"Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs — in time, in space, and in potential — the tidy anthropocentric proscenium of our ancestors. We gaze across billions of light-years of space to view the Universe shortly after the Big Bang, and plumb the fine structure of matter. We peer down into the core of our planet, and the blazing interior of our star. We read the genetic language in which is written the diverse skills and propensities of every being on Earth. We uncover hidden chapters in the record of our origins, and with some anguish better understand our nature and prospects. We invent and refine agriculture, without which almost all of us would starve to death. We create medicines and vaccines that save the lives of billions. We communicate at the speed of light, and whip around the Earth in an hour and a half. We have sent dozens of ships to more than seventy worlds, and four spacecraft to the stars. We are right to rejoice in our accomplishments, to be proud that our species has been able to see so far, and to judge our merit in part by the very science that has so deflated our pretensions."
"In some respects, science has far surpassed religion in delivering awe. How is it that hardly any major religion has looked at science and concluded, "This is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant. God must be even greater than we dreamed"? Instead they say, "No, no, no! My god is a little god, and I want him to stay that way.""
"We've tended in our cosmologies to make things familiar. Despite all our best efforts, we've not been very inventive. In the West, Heaven is placid and fluffy, and Hell is like the inside of a volcano. In many stories, both realms are governed by dominance hierarchies headed by gods or devils. Monotheists talked about the king of kings. In every culture we imagined something like our own political system running the Universe. Few found the similarity suspicious."
"It took the Church until 1832 to remove Galileo's work from its list of books which Catholics were forbidden to read at the risk of dire punishment of their immortal souls."
"Ann Druyan suggests an experiment: Look back again at the pale blue dot of the preceding chapter. Take a good long look at it. Stare at the dot for any length of time and then try to convince yourself that God created the whole Universe for one of the 10 million or so species of life that inhabit that speck of dust. Now take it a step further: Imagine that everything was made just for a single shade of that species, or gender, or ethnic or religious subdivision. If this doesn't strike you as unlikely, pick another dot. Imagine it to be inhabited by a different form of intelligent life. They, too, cherish the notion of a God who has created everything for their benefit. How seriously do you take their claim?"
"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."
"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…""
"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.”"
"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."
"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."
"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."
"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."