"Before we invented civilization our ancestors lived mainly in the open out under the sky. Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away."

"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."

"The same few dozen organic molecules are used over and over again in biology for the widest variety of functions."

"Even if the aliens are short, dour, and sexually obsessed-if they're here, I want to know about them."

"There are no forbidden questions in science, no matters to sensitive or delicate to be probed, no sacred truths. That openness to new ideas, combined with the most rigorous, skeptical scrutiny of all ideas, sifts the wheat from the chaff. It makes no difference how smart, august, or beloved you are. You must prove your case in the face of determined, expert criticism. Diversity and debate are valued. Opinions are encouraged to contend"substantively and in depth."

"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 uptime 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 you 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."

"We are all flawed and creatures of our times. Is it fair to judge us by the unknown standards of the future?"

"A book is made from a tree. It is an assemblage of flat, flexible parts (still called "leaves") imprinted with dark pigmented squiggles. One glance at it and you hear the voice of another person, perhaps someone dead for thousands of years. Across the millennia, the author is speaking, clearly and silently, inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people, citizens of distant epochs, who never knew one another. Books break the shackles of time - proof that humans can work magic."

"I know of no significant advance in science that did not require major inputs from both cerebral hemispheres. This is not true for art, where apparently there are no experiments by which capable, dedicated and unbiased observers can determine to their mutual satisfaction which works are great."

"Whatever the reason we first mustered the _Apollo_ program, however mired it was in Cold War nationalism and the instruments of death, the inescapable recognition of the unity and fragility of the Earth is its clear and luminous dividend, the unexpected final gift of _Apollo_. What began in deadly competition has helped us to see that global cooperation is the essential precondition for our survival.Travel is broadening. It's time to hit the road again."

"There is some evidence that dreaming is necessary. When people or other mammals are deprived of REM sleep (by awakening them as soon as the characteristic REM and EEG dream patterns emerge), the number of initiations of the dream state per night goes up, and, in severe cases, daytime hallucinations-that is, waking dreams-occur."

"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people."

"While ritual, emotion and reasoning are all significant aspects of human nature, the most nearly unique human characteristic is the ability to associate abstractly and to reason. Curiosity and the urge to solve problems are the emotional hallmarks of our species; and the most characteristically human activities are mathematics, science, technology, music and the arts--a somewhat broader range of subjects than is usually included under the "humanities." Indeed, in its common usage this very word seems to reflect a peculiar narrowness of vision about what is human. Mathematics is as much a "humanity" as poetry."

"Our difficulties in understanding or effectuatingcommunication with other animals may arise from our reluctance to grasp unfamiliar ways of dealing with the world."

"Nevertheless, (Jefferson) believed that the habit of skepticism is an essential prerequisite for responsible citizenship. He argued that the cost of education is trivial compared to the cost of ignorance, of leaving government to the wolves. He taught that the country is safe only when the people rule."

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

"You could just as well say that an agnostic is a deeply religious person with at least a rudimentary knowledge of human fallibility."

"Across the sea of space, the stars are other suns."

"And despite the insignificance of the instant we have so far occupied in cosmic time, it is clear that what happens on and near Earth at the beginning of the second cosmic year will depend very much on the scientific wisdom and the distinctly human sensitivity of mankind."

"Once we lose our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe which dwarfs -- in time, in space, and in potential -- the tidy anthropocentric proscenium of our ancestors."

"Evolution is adventitious and not foresighted. Only through the deaths of an immense number of slightly maladapted organisms are we, brains and all, here today."

"There is every reason to think that in the coming years Mars and its mysteries will become increasingly familiar to the inhabitants of the Planet Earth."

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

"Those who make uncritical observations or fraudulent claims lead us into error and deflect us from the major human goal of understanding how the world works. It is for this reason that playing fast and loose with the truth is a very serious matter."

"Deluded or not, supporters of superstition and pseudoscience are human beings with real feelings, who, like the skeptics, 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."

"The school systems, it seems to me have a attitude of discouragement of asking fundamental questions, if a 5 or 6 year old asks why the moon is round or why the grass is green? The usual adult answer, at least in my experience is to discourage the child.what color did you expect the moon to be? square? what color you expect the grass to be?blue?Instead of saying that those are interesting questions and lets try to find the answers or maybe nobody knows the answers and when you grow up you would be able to discover the answers.It would be very healthy for human species if we could have less discouragement and more scientists. - Carl Sagan (In an interview with Magnus Magnusson, 1988)"

"There are many hypotheses in science which are wrong. That's perfectly all right: it's the aperture to finding out what's right. Science is a self-correcting process."

"When you make the finding yourself - even if you're the last person on Earth to see the light - you'll never forget it."

"Our probable ancestors, Homo erectus and Homo habilis -now extinct- are classified as of the same genus (Homo) but of different species, although no one (at least lately) has attempted the appropriate experiments to see if crosses of them with us would produce fertile offspring."

"We are all star stuff."

"But if they called everything divine which they do not understand, why, there would be no end of divine beings."

"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 they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense."

"[In] everyday life, it is very rare that we are confronted with new facts about events of long ago. Our memories are almost never challenged. They can, instead, be frozen in place, no matter how flawed they are, or become a work in continual artistic revision."

"Civilization is a product of the cerebral cortex."

"Do dogs feel for humans something akin to religious ecstasy? What other strong or subtle emotions are felt by animals that do not communicate with us?"

"Neuroanatomy, political history, and introspection all offer evidence that human beings are quite capable of resisting the urge to surrender to every impulse of reptilian core of brain."

"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."

"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."

"You squeeze the eyedropper, and a drop of pond water drips out onto the microscope stage. You look at the projected image. The drop is full of life - strange beings swimming, crawling, tumbling; high dramas of pursuit and escape, triumph and tragedy. This is a world populated by beings far more exotic than in any science fiction movie..."

"Their position seems to be that their God is so great he doesn't even have to exist."

"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."

"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." (1980)"

"For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring."

"But, Jefferson worried that the people - and the argument goes back to Thucydides and Aristotle - are easily misled. He also stressed, passionately and repeatedly, that it was essential for the people to understand the risks and benefits of government, to educate themselves, and to involve themselves in the political process. Without that, he said, the wolves will take over."

"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."

"We have examined the universe in space and seen that we live on a mote of dust circling a humdrum star in the remotest corner of an obscure galaxy. And if we are a speck in the immensity of space, we also occupy an instant in the expanse of ages."

"Could we possible manage the next phase of human history without first dealing with this penchant for dehumanizing the adversary?"

"In addition, human beings have, in the most recent few tenths of a percent of our existence, invented not only extra-genetic but also extrasomatic knowledge: information stored outside our bodies, of which writing is the most notable example."

"People are not stupid. They believe things for reasons. The last way for skeptics to get the attention of bright, curious, intelligent people is to belittle or condescend or to show arrogance toward their beliefs."

"Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value the may have in inspiring us or in exciting our sense of wonder."