Quotes from Carl Sagan

We seem to crave privilege, merited not by our works but by our birth, by the mere fact that, say, we are humans and born on Earth. We might call it the anthropocentric - the 'human-centered' - conceit. This conceit is brought close to culmination in the notion that we are created in God's image: The Creator and Ruler of the entire Universe looks just like me. My, what a coincidence! How convenient and satisfying!

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?

Many of the problems facing us may be soluble, but only if we are willing to embrace brilliant, daring and complex solutions. Such solutions require brilliant, daring and complex people. I believe that there are many more of them around—in every nation, ethnic group and degree of affluence—than we realize.

It is very difficult to evolve by altering the deep fabric of life; any change there is likely to be lethal. But fundamental change can be accomplished by the addition of new systems on top of old ones.

if we have several hundred or several thousand cultures, each with its own cosmology, we should not be astounded if, every now and then, purely by chance, one of them proposes an idea that is not only correct but also impossible for them to have deduced.

There is nothing inhuman about an intelligent machine; it is indeed an expression of those superb intellectual capabilities that only human beings, of all the creatures on our planet, now possess.

is it really true that we can't afford one attack helicopter's worth of seed corn to listen to the stars?

Religious sects, established and marginal, and some newly invented for the purpose, were dissecting the theological implications of the Message. Some thought it was from God, and some from the Devil. Astonishingly, some were even unsure.

Since much of the ocean floor remains unexplored (except perhaps for still-classified data acquired by the U.S. and Soviet navies), we may know more about the surface topography of Venus than about any other planet, Earth included.

E]ven laws of Nature are not absolutely certain. There may be new circumstances never before examined – inside black holes, say, or within the electron, or close to the speed of light – where even our vaunted laws of Nature break down and, however valid they may be in ordinary circumstances, need correction.

Science gropes and staggers toward improved understanding.

In the diagnosis of disease, Hippocrates introduced elements of the scientific method. He urged careful and meticulous observation: "Leave nothing to chance. Overlook nothing. Combine contradictory observations. Allow yourself enough time.

But in introducing me simultaneously to skepticism and to wonder, they taught me the two uneasily cohabiting modes of thought that are central to the scientific method.

In our time we have less severe standards. We tell children about Santa Claus, the Easter Bunny, and the Tooth Fairy for reasons we think emotionally sound, but then disabuse them of these myths before they're grown. Why retract? Because their well-being as adults depends on them knowing the world as it really is. We worry, and for good reason, about adults who still believe in Santa Claus.

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

Many of the dangers we face indeed arise from science and technology—but, more fundamentally, because we have become powerful without becoming commensurately wise. The world-altering powers that technology has delivered into our hands now require a degree of consideration and foresight that has never before been asked of us.

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

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. But a kind of Gresham's Law prevails in popular culture by which bad science drives out good.

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.

Voltaire argued that if God did not exist Man would be obliged to invent him, and was reviled for the remark.

We are, each of us, largely responsible for what gets put into our brains, for what, as adults, we wind up caring for and knowing about. No longer at the mercy of the reptile brain, we can change ourselves.

If a marker were to be erected today, it might read, in homage to his scientific courage: "He preferred the hard truth to his dearest illusions.

It does no harm to the romance of the sunset to know a little about it.

Books are key to understanding the world and participating in a democratic society.