Carl Sagan Quotes

What counts is not what sounds plausible, not what we would like to believe, not what one or two witnesses claim, but only what is supported by hard evidence rigorously and skeptically examined. Extraordinary claims require extraordinary evidence.

Extraordinary observations require extraordinary evidence.

We must never assume that which is incapable of proof.

Conservatives need to go where the facts, not ideology, take them.

I ask you to believe nothing that you cannot verify for yourself.

I’m a skeptic not because I do not want to believe, but because I want to know. How can we tell the difference between what we would like to be true and what is actually true? The answer is science.

[E]xceptional claims demand exceptional evidence.

God forbid that Truth should be confined to Mathematical Demonstration!

Everything that people say is testable.

Skeptics question the validity of a particular claim by calling for evidence to prove or disprove it.

Absence of evidence is not evidence of absence.

My colleagues have learned to respect nothing but evidence, and to believe that their highest duty lies in submitting to it, however it may jar against their inclinations.

In my opinion, it helps enormously to know why something is true, rather than being told it is true, for why should you believe me? Never believe anything on the authority of a single person but seek confirmation — and reason is the best confirmation

Happily I had very early learned the fallacy of building much on logic and verbal argument. Single sets of truths I knew to be as little conclusive in theology as in physics; and, in one as in the other, no theory to be worth anything, however plausibly backed up with Scripture texts or facts, which was not gathered bona fide from the analysis of all the attainable phenomena, and verified wherever possible by experiment.

Do not believe just because you want to believe.

I cannot live on myths; somehow, science convinces me more easily. I am prone to lean towards science, ethics, and philosophy rather than myth, religion, and rituals.

Throughout history, every mystery ever solved has turned out to be NOT magic.

If someone doesn’t value evidence, what evidence are you going to provide that proves they should value evidence. If someone doesn’t value logic, what logical argument would you invoke to prove they should value logic?

I believe in things that have proof.

...Thomas did not believe the resurrection [John 20:25], and, as they say, would not believe without having ocular and manual demonstration himself. So neither will I, and the reason is equally as good for me, and for every other person, as for Thomas.

No evidence or proof of the existence of a God has been found in the phenomena of nature, based on experience.

Science is a philosophy of discovery; intelligent design is a philosophy of ignorance... Something fundamamental is going on in people's minds when they confront things they don't understnd.

Exceptional claims, require exceptional evidence.

Truth does not demand belief. Scientists do not join hands every Sunday, singing, 'Yes, gravity is real! I will have faith!'

It annoys me that the burden of proof is on us. It should be "You came up with the idea. Why do you believe it?" I could tell you I've got superpowers. But I can't go up to people saying "Prove I can't fly." They'd go: "What do you mean 'Prove you can't fly'? Prove you can!"