Top 500 Carl Sagan Quotes (2026 Update)
Page 9 of 10

401. “We live at a moment when our relationships to each other, and to all other beings with whom we share this planet, are up for grabs.”

— Carl Sagan

402. “The world is so exquisite with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there’s little good evidence. Far better it seems to me, in our vulnerability, is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides.”

— Carl Sagan

403. “Science cuts two ways, of course; its products can be used for both good and evil. But there’s no turning back from science. The early warnings about technological dangers also come from science.”

— Carl Sagan

404. “If we’re capable of conjuring up terrifying monsters in childhood, why shouldn’t some of us, at least on occasion, be able to fantasize something similar, something truly horrifying, a shared delusion, as adults?”

— Carl Sagan

405. “In the vastness of the Cosmos there must be other civilizations far older and more advanced than ours.”

— Carl Sagan

406. “But humans have deliberately selected which plants and animals shall live and which shall die for thousands of years. We are surrounded from babyhood by familiar farm and domestic animals, fruits and trees and vegetables. Where do they come from? Were they once free-living in the wild and then induced to adopt a less strenuous life on the farm? No, the truth is quite different. They are, most of them, made by us.”

— Carl Sagan

407. “La causa de la miseria humana evitable no suele ser tanto la estupidez como la ignorancia, particularmente la ignorancia de nosotros mismos.”

— Carl Sagan

408. “There is a place with four suns in the sky-red, white, blue, and yellow; two of them are so close together that they touch, and star-stuff flows between them. I know of a world with a million moons. I know of a sun the size of the Earth-and made of diamond... The universe is vast and awesome, and for the first time we are becoming part of it.”

— Carl Sagan

409. “If we do not speak for Earth, who will? If we are not committed to our own survival, who will be?”

— Carl Sagan

410. “Ours is the first generation that has grown up with science-fiction ideas.”

— Carl Sagan

411. “Few scientists now dispute that today’s soaring levels of carbon dioxide and other gases in the atmosphere will cause global temperature averages to rise by as much as nine degrees Fahrenheit sometime after the year 2000.”

— Carl Sagan

412. “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.”

— Carl Sagan

413. “One of the central issues in the world population crisis is poverty.”

— Carl Sagan

414. “Nature does not always conform to our predispositions and preferences, to what we deem comfortable and easy to understand.”

— Carl Sagan

415. “All inquires carry with them some element of risk. There is no guarantee that the universe will conform to our predispositions.”

— Carl Sagan

416. “We’ve arranged a civilization in which most crucial elements profoundly depend on science and technology.”

— Carl Sagan

417. “In more than one respect, the exploring of the Solar System and homesteading other worlds constitutes the beginning, much more than the end, of history.”

— Carl Sagan

418. “I would be very ashamed of my civilization if we did not try to find out if there is life in outer space.”

— Carl Sagan

419. “The scientific way of thinking is at once imaginative and disciplined. This is central to its success. Science invites us to let the facts in, even when they don’t conform to our preconceptions. It counsels us to carry alternative hypotheses in our heads and see which best fit the facts. It urges on us a delicate balance between no-holds-barred openness to new ideas, however heretical, and the most rigorous skeptical scrutiny of everything – new ideas and established wisdom.”

— Carl Sagan

420. “All colours are arbitrary.”

— Carl Sagan

421. “A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism.”

— Carl Sagan

422. “Cleverly designed experiments are the key.”

— Carl Sagan

423. “Our intelligence is imperfect, surely, and newly arisen; the ease with which it can be sweet-talked, overwhelmed, or subverted by other hardwired propensities – sometimes themselves disguised as the cool light of reason – is worrisome.”

— Carl Sagan

424. “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

425. “Modern Darwinism makes it abundantly clear that many less ruthless traits, some not always admired by robber barons and Fuhrers – altruism, general intelligence, compassion – may be the key to survival.”

— Carl Sagan

426. “For years I’ve been stressing with regard to UFOs that extraordinary claims require extraordinary evidence.”

— Carl Sagan

427. “Part of the resistance to Darwin and Wallace derives from our difficulty in imagining the passage of the millennia, much less the aeons. What does seventy million years mean to beings who live only one-millionth as long? We are like butterflies who flutter for a day and think it is forever.”

— Carl Sagan

428. “Much of human history can, I think, be described as a gradual and sometimes painful liberation from provincialism, the emerging awareness that there is more to the world than was generally believed by our ancestors.”

— Carl Sagan

429. “Humans are very good at dreaming, although you’d never know it from your television.”

— Carl Sagan

430. “When you look more generally at life on Earth, you find that it is all the same kind of life. There are not many different kinds; there’s only one kind. It uses about fifty fundamental biological building blocks, organic molecules.”

— Carl Sagan

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

— Carl Sagan

432. “For all I know we may be visited by a different extraterrestrial civilization every second Tuesday, but there’s no support for this appealing idea. The extraordinary claims are not supported by extraordinary evidence.”

— Carl Sagan

433. “Coal, oil and gas are called fossil fuels, because they are mostly made of the fossil remains of beings from long ago. The chemical energy within them is a kind of stored sunlight originally accumulated by ancient plants. Our civilization runs by burning the remains of humble creatures who inhabited the Earth hundreds of millions of years before the first humans came on the scene. Like some ghastly cannibal cult, we subsist on the dead bodies of our ancestors and distant relatives.”

— Carl Sagan

434. “We are not smart enough to decide which pieces of knowledge are permissible and which are not.”

— Carl Sagan

435. “There is no single ultimate truth to be achieved, after which all the scientists can retire. And because this is so, the world is far more interesting, both.”

— Carl Sagan

436. “We are prodding, challenging, seeking contradictions or small, persistent residual errors, proposing alternative explanations, encouraging heresy. We give our highest rewards to those who convincingly disprove established beliefs.”

— Carl Sagan

437. “What’s the harm of a little mystification? It sure beats boring statistical analyses.”

— Carl Sagan

438. “The understanding of the intent of the artist which I can achieve when high sometimes carries over to when I’m down. This is one of many human frontiers which cannabis has helped me traverse.”

— Carl Sagan

439. “If there is as a continuum from self-reproducing molecules, such as DNA, to microbes, and an evolutionary sequence continuum from microbes to humans, why should we imagine that continuum to stop at humans?”

— Carl Sagan

440. “Every age has its peculiar folly; some scheme, project, or phantasy into which it plunges, spurred on either by the love of gain, the necessity of excitement, or the mere force of imitation. Failing in these, it has some madness, to which it is goaded by political or religious causes, or both combined.”

— Carl Sagan

441. “You are a collection of almost identical molecules with a different collective label. But is that all? Is there nothing in here but molecules? Some people find this idea somehow demeaning to human dignity. For myself, I find it elevating that our universe permits the evolution of molecular machines as intricate and subtle as we.”

— Carl Sagan

442. “Prejudice means literally pre-judgment, the rejection of a contention out of hand, before examining the evidence. Prejudice is the result of powerful emotions, not of sound reasoning.”

— Carl Sagan

443. “In any case, we do not advance the human cause by refusing to consider ideas that make us frightened.”

— Carl Sagan

444. “I reject the notion that science is by its nature secretive. Its culture and ethos are, and for very good reason, collective, collaborative, and communicative.”

— Carl Sagan

445. “If the press descended, the science would surely suffer.”

— Carl Sagan

446. “Apart from the social insects, no other species has been clever enough to invent war It is an institution optimally configured to benefit the alphas.”

— Carl Sagan

447. “If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another.”

— Carl Sagan

448. “For ages men had used sticks to club and spear each other – Anaximander of Miletus used the stick to measure time.”

— Carl Sagan

449. “Cosmos is a Greek word for the order of the universe.”

— Carl Sagan

450. “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.”

— Carl Sagan