Carl Sagan

If it can be destroyed by the truth, it deserves to be destroyed by the truth.

Extinction is the rule. Survival is the exception.

One glance at a book and you hear the voice of another person, perhaps someone dead for 1,000 years. To read is to voyage through time.

Science is not only compatible with spirituality; it is a profound source of spirituality.

Extraordinary claims require extraordinary evidence.

But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright brothers. But they also laughed at Bozo the Clown.

Science is a way of thinking much more than it is a body of knowledge.

Every one of us is, in the cosmic perspective, precious. If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another.

The cosmos is within us. We are made of star-stuff. We are a way for the universe to know itself.

The beauty of a living thing is not the atoms that go into it, but the way those atoms are put together.

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what's true.

Somewhere, something incredible is waiting to be known.

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

We are star stuff which has taken its destiny into its own hands.

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

We are a way for the cosmos to know itself.

We can judge our progress by the courage of our questions and the depth of our answers, our willingness to embrace what is true rather than what feels good.

If you wish to make an apple pie from scratch, you must first invent the universe.