Explore Quotes by Carl Sagan

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.

Scientists constantly get clobbered with the idea that we spent 27 billion dollars on the Apollo programs, and are asked "What more do you want?" We didn't spend it; it was done for political reasons. ... Apollo was a response to the Bay of Pigs fiasco and to the successful orbital flight of Yuri Gagarin. President Kennedy's objective was not to find out the origin of the moon by the end of the decade; rather it was to put a man on the moon and bring him back, and we did that.

[N]o scientist likes to be criticized. ... But you don't reply to critics: "Wait a minute, wait a minute; this is a really good idea. I'm very fond of it. It's done you no harm. Please don't attack it." That's not the way it goes. The hard but just rule is that if the ideas don't work, you must throw them away. Don't waste any neurons on what doesn't work. Devote those neurons to new ideas that better explain the data. Valid criticism is doing you a favor.

I believe that in every person is a kind of circuit which resonates to intellectual discovery-and the idea is to make that resonance work

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.

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.

A religion old or new, that stressed the magnificence of the universe as revealed by modern science, might be able to draw forth reserves of reverence and awe hardly tapped by the conventional faiths. Sooner or later such a religion will emerge.

Imagine a room awash in gasoline, and there are two implacable enemies in that room. One of them has nine thousand matches. The other has seven thousand matches. Each of them is concerned about who's ahead, who's stronger. Well that's the kind of situation we are actually in. The amount of weapons that are available to the United States and the Soviet Union are so bloated, so grossly in excess of what's needed to dissuade the other, that if it weren't so tragic, it would be laughable. What is necessary is to reduce the matches and to clean up the gasoline.

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.

My fundamental premise about the brain is that its workings - what we sometimes call "mind" - are a consequence of its anatomy and physiology, and nothing more.

We are an intelligent species and the use of our intelligence quite properly gives us pleasure. In this respect the brain is like a muscle. When we think well, we feel good. Understanding is a kind of ecstasy.

Our children long for realistic maps of the future that they can be proud of. Where are the cartographers of human purpose?

It would be wryly interesting if in human history the cultivation of marijuana led generally to the invention of agriculture, and thereby to civilization.

Recent research shows that many children without enough to eat wind up with diminished capacity to understand and learn (“cognitive impairment” ). Children don't have to be starving for this to happen. Even mild undernourishment — the kind most common among poor people in America — can do it.

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.

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.

Virtually every major technological advance in the history of the human species - back to the invention of stone tools and the domestication of fire - has been ethically ambiguous.

At the extremes it is difficult to distinguish pseudoscience from rigid, doctrinaire religion.

Is it fair to be suspicious of an entire profession because of a few bad apples? There are at least two important differences, it seems to me. First, no one doubts that science actually works, whatever mistaken and fraudulent claim may from time to time be offered. But whether there are any miraculous cures from faith-healing, beyond the body's own ability to cure itself, is very much at issue. Secondly, the expose' of fraud and error in science is made almost exclusively by science. But the exposure of fraud and error in faith-healing is almost never done by other faith-healers.

Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history.

Since World War II, Japan has spawned enormous numbers of new religions featuring the supernatural.... In Thailand, diseases are treated with pills manufactured from pulverized sacred Scripture. Witches are today being burned in South Africa.... The worldwide TM [Transcendental Meditation] organization has an estimated valuation of $3 billion. For a fee, they promise to make you invisible, to enable you to fly.