Carl Sagan

The nuclear arms race is like two sworn enemies standing waist deep in gasoline, one with three matches, the other with five.

We are, in the most profound sense, children of the cosmos.

The universe is a symphony of stars and planets, of galaxies and nebulae, of life and death.

We are privileged to live in an age when the universe is beginning to reveal its secrets.

The universe is not only stranger than we imagine, it is stranger than we can imagine.

The cosmos is a vast and ancient place, and we are but a small part of it.

Our passion for knowledge, our curiosity, our hunger for truth, these are the things that make us human.

The universe is a vast and beautiful place, and we are lucky to be a part of it.

Every star in the night sky is a sun, and many of them have planets.

We are the product of 15 billion years of cosmic evolution.

An atheist is a man who has no invisible means of support.

If we are to survive, we must have a certain measure of inspired impertinence.

Absence of evidence is not evidence of absence.

We make our world significant by the courage of our questions and by the depth of our answers.

For small creatures such as we the vastness is bearable only through love.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pie were made in the interiors of collapsing stars. We are made of starstuff.

If you want to save your child from polio, you can pray or you can inoculate. ... We've seen what prayer can do. Inoculation is better.

The truth may be puzzling. It may take some effort to grasp. It may be counterintuitive. It may contradict deeply held prejudices. It may not be what we want to hear. But our preferences do not determine what's true.

A book is made of paper, ink, and imagination.

Better the hard truth, I say, than the comforting fantasy.