Carl Sagan

The notion that science and spirituality are somehow mutually exclusive does a disservice to both.

The cosmos is full beyond measure of elegant truths, of exquisite interrelationships, of the awesome machinery of the universe.

We have not been to the stars, but the stars have come to us.

What an astonishing thing a book is. It's a flat object made from a tree with flexible parts on which are imprinted many curious squiggles. But one glance at it and you're inside the mind of another human being, perhaps someone dead for thousands of years. Across the millennia, an author is speaking clearly and silently inside your head, directly to you. Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. Books prove that humans can work magic.

The price of skepticism is eternal vigilance.

The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.

The cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the cosmos stir up a tingling sensation, a slight shuddering, as if of a distant memory of falling from a great height. We know we are approaching the greatest of mysteries.

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.

We are a part of the universe, and the universe is a part of us.

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

The cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us—there's a tingling in the spine, a catch in the throat, a faint sensation, as if a distant memory, of falling from a height. We know we are approaching the greatest of mysteries.

If we long to believe in a thing, we will find a way to believe in it.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become momentary masters of a fraction of a dot.

If we are to survive, we need to understand the universe and our place in it.

A celibate clergy is an especially good idea, because it tends to suppress the inherited passion for intolerance.

How is it that hardly any major religion has looked at science and concluded, 'This is better than we thought! The Universe is much bigger than our prophets imagined, more grand, more elegant, more awe-inspiring!' Instead they say, 'No, no, no! My god is a tiny god, and I want him to stay that way.'

If we've been able to do all this, think of what we could do if we weren't so preoccupied with war and other destructive activities.

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 consonant with what we desperately want to believe. But our preferences do not determine what's true.

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

We have not been good stewards of the Earth. We have been rapacious and short-sighted.