Carl sagan quotes

Who are we, if not measured by our impact on others? That’s who we are! We’re not who we say we are, we’re not who we want to be - we are the sum of the influence and impact that we have, in our lives, on others.

One of the great commandments of science is: 'Mistrust arguments from authority.'

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.

There are in fact 100 billion galaxies, each of which contain something like a 100 billion stars. Think of how many stars, and planets, and kinds of life there may be in this vast and awesome universe.

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.

If we continue to accumulate only power and not wisdom, we will surely destroy ourselves.

The absence of evidence is not the evidence of absence.

The cosmos is within us. We are made of star stuff

Wisdom lies in understanding our limitations.

We live in a society exquisitely dependent on science and technology and yet have cleverly arranged things so that almost no one understands science and technology.

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what's true.

Your god is too small for my universe.

Life is but a momentary glimpse of the wonder of this astonishing universe, and it is sad to see so many dreaming it away on spiritual fantasy.

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.

Every star may be a sun to someone.

Better the hard truth, I say, than the comforting fantasy.

We are like butterflies who flutter for a day and think it is forever.

To live in the hearts of others is to never die in those we leave behind.

Valid criticism does you a favor.

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.

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

The cure for a fallacious argument is a better argument, not the suppression of ideas.

Science is not only compatible with spirituality; it is a profound source of spirituality.

Anything else you're interested in is not going to happen if you can't breathe the air and drink the water. Don't sit this one out. Do something. You are by accident of fate alive at an absolutely critical moment in the history of our planet.

Frederick Douglas taught that literacy is the path from slavery to freedom. There are many kinds of slavery and many kinds of freedom, but reading is still the path.

Curiosity and the urge to solve problems are the emotional hallmarks of our species.

Science is a way to not fool ourselves.

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.

I am not an atheist. An atheist is someone who has compelling evidence that there is no Judeo-Christian-Islamic God. I am not that wise, but neither do I consider there to be anything approaching adequate evidence for such a god. Why are you in such a hurry to make up your mind? Why not simply wait until there is compelling evidence?

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.

An atheist has to know a lot more than I know. An atheist is someone who knows there is no god. By some definitions atheism is very stupid.

Don't judge everyone else by your own limited experience.

History is full of people who out of fear, or ignorance, or lust for power has destroyed knowledge of immeasurable value which truly belongs to us all. We must not let it happen again.

Where we have strong emotions, we're liable to fool ourselves.

War is murder writ large.

The price we pay for anticipation of the future is anxiety about it

There are as many atoms in one molecule of DNA as there are stars in a typical galaxy.

We are rare and precious because we are alive, because we can think as well as we can. We are privileged to influence and perhaps control our future. I believe we have an obligation to fight for life on Earth - not just for ourselves, but for all those, humans and others, who came before us, and to whom we are beholden, and for all those who, if we are wise enough, will come after.

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.

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?

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 seven and a half 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.

It is the responsibility of scientists never to suppress knowledge, no matter how awkward that knowledge is, no matter how it may bother those in power; we are not smart enough to decide which pieces of knowledge are permissible, and which are not.

Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works.

Science is a way of thinking much more than it is a body of knowledge.

We are the universe experiencing itself.

Who are we, if not measured by our impact on others?

Science ... looks skeptically at all claims to knowledge, old and new. It teaches not blind obedience to those in authority but to vigorous debate, and in many respects that's the secret of its success.

When you realize that no one really knows what they are doing and that everyone is doing the best they can according to their own level of consciousness, life gets a lot easier. Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.

The illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world.

Nothing disturbs me more than the glorification of stupidity.

The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth.

The simplest thought, like the concept of the number one, has an elaborate logical underpinning.

If I finish a book a week, I will read only a few thousand books in my lifetime, about a tenth of a percent of the contents of the greatest libraries of our time. The trick is to know which books to read.

The sacred truth of science is that there are no sacred truths.

Imagination will often carry us to worlds that never were. But without it we go nowhere.

Our ancestors lived out of doors. They were as familiar with the night sky as most of us are with our favorite television programs.

The fact is that far more crime and child abuse has been committed by zealots in the name of God, Jesus and Mohammed than has ever been committed in the name of Satan. Many people don’t like that statement, but few can argue with it.

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

If you look at Earth from space you see a dot, that's here. That's home. That's us. It underscores the responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.

Some racists still reject the plain testimony written in the DNA that all the races are not only human but nearly indistinguishable. . . .

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

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.

Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage - at the very least the courage to question the conventional wisdom.

The nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five.

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.

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.

An extraterrestrial being, newly arrived on Earth - scrutinizing what we mainly present to our children in television, radio, movies, newspapers, magazines, the comics, and many books - might easily conclude that we are intent on teaching them murder, rape, cruelty, superstition, credulity, and consumerism. We keep at it, and through constant repetition many of them finally get it.

Writing is perhaps the greatest of human inventions.

An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the existence of God. I know of no such compelling evidence. Because God can be relegated to remote times and places and to ultimate causes, we would have to know a great deal more about the universe than we do now to be sure that no such God exists. To be certain of the existence of God and to be certain of the nonexistence of God seem to me to be the confident extremes in a subject so riddled with doubt and uncertainty as to inspire very little confidence indeed.

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.

Understanding is a kind of ecstasy

Knowing a great deal is not the same as being smart; intelligence is not information alone but also judgement, the manner in which information is coordinated and used.

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.

Be grateful everyday for the brief but magnificent opportunity that life provides.

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.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.

We live on a mote of dust suspended in a sunbeam

We live on a hunk of rock and metal that circles a humdrum star that is one of 400 billion other stars that make up the Milky Way Galaxy which is one of billions of other galaxies which make up a universe which may be one of a very large number, perhaps an infinite number, of other universes. That is a perspective on human life and our culture that is well worth pondering.

We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology.

We are, each of us, a multitude. Within us is a little universe.

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.

Every time you look up at the sky, every one of those points of light is a reminder that fusion power is extractable from hydrogen and other light elements, and it is an everyday reality throughout the Milky Way Galaxy.

Stars are phoenixes, rising from their own ashes.

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

The Hindu religion is the only one of the world’s great faiths dedicated to the idea that the Cosmos itself undergoes an immense, indeed an infinite, number of deaths and rebirths. It is the only religion in which the time scales correspond, no doubt by accident, to those of modern scientific cosmology. Its cycles run from our ordinary day and night to a day and night of Brahma, 8.64 billion years long, longer than the age of the Earth or the Sun and about half the time since the Big Bang.

The dumbing down of America is evident in the slow decay of substantive content, a kind of celebration of ignorance.

Our ancestors worshipped the Sun, and they were not that foolish. It makes sense to revere the Sun and the stars, for we are their children.

If you want to save your child from polio, you can pray or you can inoculate....Try science.

Ask courageous questions. Do not be satisfied with superficial answers. Be open to wonder and at the same time subject all claims to knowledge, without exception, to intense skeptical scrutiny. Be aware of human fallibility. Cherish your species and your planet.

Every cell is a triumph of natural selection, and we’re made of trillions of cells. Within us, is a little universe.

Ask courageous questions. Do not be satisfied with superficial answers.

The difference between physics and metaphysics is not that the practitioners of one are smarter than the practitioners of the other. The difference is that the metaphysicist has no laboratory.

Finding the occasional straw of truth awash in a great ocean of confusion and bamboozle requires intelligence, vigilance, dedication, and courage. But if we don't practice these tough habits of thought, we cannot hope to solve the truly serious problems that face us --- and we risk becoming a nation of suckers, up for grabs by the next charlatan who comes along.

The universe is a pretty big place. If it's just us, seems like an awful waste of space.

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

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.

The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.

You have to know the past to understand the present.

I promise to question everything my leaders tell me. I promise to use my critical faculties. I promise to develop my independence of thought. I promise to educate myself so I can make my own judgments.

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

Cosmos is a Greek word for the order of the universe. It is, in a way, the opposite of Chaos. It implies the deep interconnectedness of all things. It conveys awe for the intricate and subtle way in which the universe is put together.

But I could be wrong.

What a marvelous cooperative arrangement - plants and animals each inhaling each other's exhalations, a kind of planet-wide mutual mouth-to-stoma resuscitation, the entire elegant cycle powered by a star 150 million kilometers away.

Extraordinary claims demand extraordinary evidence

I have a foreboding of an America in my children's or grandchildren's time - [...] 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.

You can't convince a believer of anything; for their belief is not based on evidence, it's based on a deep seated need to believe

Extinction is the rule. Survival is the exception.

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

It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.

The fact that someone says something doesn't mean it's true. Doesn't mean they're lying, but it doesn't mean it's true.

Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.

The Bill of Rights decoupled religion from the state, in part because so many religions were steeped in an absolutist frame of mind - each convinced that it alone had a monopoly on the truth and therefore eager for the state to impose this truth on others.

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

Somewhere, something incredible is waiting to be known.

Our passion for learning ... is our tool for survival.

we make our world significant by the courage of our questions and the depth of our answers

Even through your hardest days, remember we are all made of stardust.

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

One of the greatest gifts adults can give - to their offspring and to their society - is to read to children.

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.

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.

The words "question" and "quest" are cognates. Only through inquiry can we discover truth.

'In his celebrated book, 'On Liberty', the English philosopher John Stuart Mill argued that silencing an opinion is "a peculiar evil." If the opinion is right, we are robbed of the "opportunity of exchanging error for truth"; and if it's wrong, we are deprived of a deeper understanding of the truth in its "collision with error." If we know only our own side of the argument, we hardly know even that: it becomes stale, soon learned by rote, untested, a pallid and lifeless truth.'

The Cosmos is all that is or was or ever will be. Our feeblest contemplations of the Cosmos stir us -- there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries.

.. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the 'Momentary' masters of a 'Fraction' of a 'Dot'