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Home > Dictionary of Science Quotations > Scientist Names Index S > Carl Sagan Quotes > Knowledge

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Carl Sagan
(9 Nov 1934 - 20 Dec 1996)

American astronomer, exobiologist and writer remembered for popularizing astronomy and science, especially with his public television series Cosmos. Its accompanying book spent seventy weeks on The New York Times bestseller list. He was an adviser to NASA for the Mariner, Voyager, and Viking unmanned space missions.



[I]magine you want to know the sex of your unborn child. There are several approaches. You could, for example, do what the late film star ... Cary Grant did before he was an actor: In a carnival or fair or consulting room, you suspend a watch or a plumb bob above the abdomen of the expectant mother; if it swings left-right it's a boy, and if it swings forward-back it's a girl. The method works one time in two. Of course he was out of there before the baby was born, so he never heard from customers who complained he got it wrong. ... But if you really want to know, then you go to amniocentesis, or to sonograms; and there your chance of being right is 99 out of 100. ... If you really want to know, you go to science.
— Carl Sagan
In 'Wonder and Skepticism', Skeptical Enquirer (Jan-Feb 1995), 19, No. 1.
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Children [are] born with a zest for knowledge, aware that they must live in a future molded by science, but so often convinced by their culture that science is not for them.
— Carl Sagan
In 'With Science on Our Side', Washington Post (9 Jan 1994).
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For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal universe for us is one very much like the universe we inhabit. And I would guess that this is not really much of a coincidence.
— Carl Sagan
Concluding paragraph, 'Can We know the Universe? Reflections on a Grain of Salt', Broca's Brain (1979, 1986), 21.
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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. …
— Carl Sagan
Quoted in Lily Splane, Quantum Consciousness (2004), 80.
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My deeply held belief is that if a god of anything like the traditional sort exists, our curiosity and intelligence were provided by such a god…on the other hand if such a god does not exist then our curiosity and intelligence are the essential tools for survival. In either case the enterprise of knowledge is essential for the welfare of the human species.
— Carl Sagan
In Broca’s Brain: Reflections on the Romance of Science (1979), 341.
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Science arouses a soaring sense of wonder. But so does pseudoscience. Sparse and poor popularizations of science abandon ecological niches that pseudoscience promptly fills. If it were widely understood that claims to knowledge require adequate evidence before they can be accepted, there would be no room for pseudoscience.
— Carl Sagan
The Demon-Haunted World: Science as a Candle in the Dark (1996), 6.
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Science is a way of thinking much more than it is a body of knowledge.
— Carl Sagan
Broca’s Brain: Reflections on the Romance of Science (1979, 1986), 15.
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Science is far from a perfect instrument of knowledge. It’s just the best one we have. In this respect, as in many others, it’s like democracy.
— Carl Sagan
In 'With Science on Our Side', Washington Post (9 Jan 1994).
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The suppression of uncomfortable ideas may be common in religion or in politics, but it is not the path to knowledge; it has no in the endeavor of science. We do not know in advance who will discover fundamental insights.
— Carl Sagan
In Cosmos (1985), 74.
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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.
— Carl Sagan
Cosmos (1985), 275.
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Too much openness and you accept every notion, idea, and hypothesis—which is tantamount to knowing nothing. Too much skepticism—especially rejection of new ideas before they are adequately tested—and you're not only unpleasantly grumpy, but also closed to the advance of science. A judicious mix is what we need.
— Carl Sagan
In 'Wonder and Skepticism', Skeptical Enquirer (Jan-Feb 1995), 19, No. 1.
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We are a way for the cosmos to know itself.
— Carl Sagan
From Carl Sagan's narration on a promotional video for the television series Cosmos.
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We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology.
— Carl Sagan
In 'Why We Need To Understand Science', The Skeptical Inquirer (Spring 1990), 14, No. 3.
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Who is running the science and technology in a democracy if the people don’t know anything about it?
— Carl Sagan
From transcript of interview on PBS TV show, Charlie Rose (27 May 1996). On Charlie Rose website.
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Carl Sagan quote Advances in medicine and agriculture
A bean farmer checks her crop in Congo. Photo by Neil Palmer (CIAT). CC2.0 (source)

See also:
  • 9 Nov - short biography, births, deaths and events on date of Sagan's birth.
  • Carl Sagan - context of quote “Advances in medicine and agriculture” - Medium image (500 x 250 px)
  • Carl Sagan - context of quote “Advances in medicine and agriculture” - Large image (800 x 400 px)
  • Carl Sagan - context of quote A Subject Called Chemistry - Medium image (500 x 350 px)
  • Carl Sagan - context of quote A Subject Called Chemistry - Large image (800 x 600 px)
  • Carl Sagan: A Life in the Cosmos, by William Poundstone. - book suggestion.
  • Booklist for Carl Sagan.

Carl Sagan Thumbnail 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. (1987) -- Carl Sagan
Quotations by:Albert EinsteinIsaac NewtonLord KelvinCharles DarwinSrinivasa RamanujanCarl SaganFlorence NightingaleThomas EdisonAristotleMarie CurieBenjamin FranklinWinston ChurchillGalileo GalileiSigmund FreudRobert BunsenLouis PasteurTheodore RooseveltAbraham LincolnRonald ReaganLeonardo DaVinciMichio KakuKarl PopperJohann GoetheRobert OppenheimerCharles Kettering  ... (more people)

Quotations about:Atomic  BombBiologyChemistryDeforestationEngineeringAnatomyAstronomyBacteriaBiochemistryBotanyConservationDinosaurEnvironmentFractalGeneticsGeologyHistory of ScienceInventionJupiterKnowledgeLoveMathematicsMeasurementMedicineNatural ResourceOrganic ChemistryPhysicsPhysicianQuantum TheoryResearchScience and ArtTeacherTechnologyUniverseVolcanoVirusWind PowerWomen ScientistsX-RaysYouthZoology  ... (more topics)
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