Quotes from Carl Sagan

Humans - who enslave, castrate, experiment on, and fillet other animals - have had an understandable penchant for pretending animals do not feel pain.

If we say that God has always been, why not save a step and conclude that the universe has always been?

The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking - it's that credulous and confused thinking can be much more lethal in ways it was never before.

Knowing a great deal is not the same as being smart; intelligence is not information alone but also judgement, the manner in which information is coordinated and used.

In the deepest sense the search for extraterrestrial intelligence is a search for ourselves.

The professed function of the nuclear weapons on each side is to prevent the other side from using their nuclear weapons. If that's all it is, then we've gotta as: how many nuclear weapons do you need to do that?

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.

Skeptical scrutiny is the means, in both science and religion, by which deep thoughts can be winnowed from deep nonsense.

The Hindu religion is the only of the World's great faiths dedicated to the idea that the Cosmos itself undergoes an immense, indeed an infinite, number of deaths and rebirths.

A multitude of aspects of the natural world that were considered miraculous only a few generations ago are now thoroughly understood in terms of physics and chemistry.

Has there ever been a religion with the prophetic accuracy and reliability of science? . . . No other human institution comes close.

Religions are often state-protected nurseries of pseudoscience, although there's no reason why religions have to play that role. In a way, it's an artefact from times long gone.

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.

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 goodevidence.

Those afraid of the universe as it really is, those who pretend to nonexistent knowledge and envision a Cosmos centered on human beings will prefer the fleeting comforts of superstition.

Science is far from a perfect instrument of knowledge. It's just the best we have.

Science is more than a body of knowledge. It's a way of thinking: a way of skeptically interrogating the universe.

You probably don't need more weapons than what's required to destroy every city on earth. There's only 2,300 cities. So, the United States, by that criteria, only needs 2,300 nuclear weapons - well, we've got more than 25,000!

I don't want to believe. I want to know.

The cure for a fallacious argument is a better argument, not the suppression of ideas.

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

The universe is not required to be in perfect harmony with human ambition.

The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home.

Science is a way to not fool ourselves.