Carl Sagan

In many myths, the one possibility the gods are most anxious about is that humans will discover some secret of immortality or even... attempt to stride the high heavens. ...It's a little bit like the rich imposing poverty on the poor and then asking to be loved because of it.

The history of science—especially physics—has in part been the tension between the natural tendency to project our everyday experience on the universe and the universe's noncompliance...

Perhaps one per cent of the time, someone who has an idea that smells, feels and looks indistinguishable from the usual run of pseudoscience will turn out to be right. Maybe some undiscovered reptile left over from the Cretaceous period will indeed be found in Loch Ness or the Congo Republic; or we will find artefacts of an advanced, non-human species elsewhere in the solar system. At the time of writing there are three claims in the ESP field which, in my opinion, deserve serious study: (1) that by thought alone humans can (barely) affect random number generators in computers; (2) that people under mild sensory deprivation can receive thoughts or images 'projected' at them; and (3) that young children sometimes report the details of a previous life, which upon checking turn out to be accurate and which they could not have known about in any other way than reincarnation. I pick these claims not because I think they're likely to be valid (I don't), but as examples of contentions that might be true. The last three have at least some, although still dubious, experimental support. Of course, I could be wrong.

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

Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science — by far the most successful claim to knowledge accessible to humans — teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us.

The enterprise of knowledge is consistent surely with science; it should be with religion, and it is essential for the welfare of the human species.

Appeal to ignorance — the claim that whatever has not been proved false must be true, and vice versa (e.g. There is no compelling evidence that UFOs are not visiting the Earth; therefore UFOs exist — and there is intelligent life elsewhere in the universe. Or: There may be seventy kazillion other worlds, but not one is known to have the moral advancement of the Earth, so we're still central to the Universe.) This impatience with ambiguity can be criticized in the phrase: absence of evidence is not evidence of absence.

Education on the value of free speech and the other freedoms reserved by the Bill of Rights, about what happens when you don't have them, and about how to exercise and protect them, should be an essential prerequisite for being an American citizen — or indeed a citizen of any nation, the more so to the degree that such rights remain unprotected. 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.

Superstition is marked not by its pretension to a body of knowledge but by its method of seeking truth.

When we consider the founders of our nation: Jefferson, Washington, Samuel and John Adams, Madison and Monroe, Benjamin Franklin, Tom Paine and many others; we have before us a list of at least ten and maybe even dozens of great political leaders. They were well educated. Products of the European Enlightenment, they were students of history. They knew human fallibility and weakness and corruptibility. They were fluent in the English language. They wrote their own speeches. They were realistic and practical, and at the same time motivated by high principles. They were not checking the pollsters on what to think this week. They knew what to think. They were comfortable with long-term thinking, planning even further ahead than the next election. They were self-sufficient, not requiring careers as politicians or lobbyists to make a living. They were able to bring out the best in us. They were interested in and, at least two of them, fluent in science. They attempted to set a course for the United States into the far future — not so much by establishing laws as by setting limits on what kinds of laws could be passed. The Constitution and its Bill of Rights have done remarkably well, constituting, despite human weaknesses, a machine able, more often than not, to correct its own trajectory. At that time, there were only about two and a half million citizens of the United States. Today there are about a hundred times more. So if there were ten people of the caliber of Thomas Jefferson then, there ought to be 10 x 100 = 1,000 Thomas Jefferson's today. Where are they?

If a Creator God exists, would He or She or It... prefer a kind of sodden blockhead who worships while understanding nothing? Or would He prefer His votaries to admire the real universe in all its intracacy?

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