We have heard the rationales offered by the nuclear superpowers. We know who speaks for the nations. But who speaks for the human species? Who speaks….

We are a way for the cosmos to know itself..

Discussing the possibilities of extraterrestrial life: I would love it even if they were short, sullen, grumpy and sexually obsessed. But there just ….

What an astonishing thing a book is..

This oak tree and me, we're made of the same stuff..

We are, in a way, temporary ambulatory repositories for our nucleic acids. This does not deny our humanity; it does not prevent us from pursuing the ….

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

Books permit us to voyage through time, to tap the wisdom of our ancestors..

Your religion assumes that people are children and need a boogeyman so they'll behave. You want people to believe in God so they'll obey the law. Tha….

Science is a way of thinking much more than it is a body of knowledge. Its goal is to find out how the world works, to seek what regularities there m….

What is called for is an exquisite balance between two conflicting needs: the most skeptical scrutiny of all hypotheses that are served up to us and ….

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 ar….

First rule in government spending: why build one when you can have two at twice the price?.

I think the discomfort that some people feel in going to the monkey cages at the zoo is a warning sign..

We wish to find the truth, no matter where it lies. But to find the truth we need imagination and skepticism both. We will not be afraid to speculate….

The open road still softly calls, like a nearly forgotten song of childhood.

Our loyalties are to the species and the planet. We speak for Earth..

You're an interesting species, an interesting mix. You're capable of such beautiful dreams and such horrible nightmares. You feel so lost, so cut off….

In more than one respect, the exploring of the Solar System and homesteading other worlds constitutes the beginning, much more than the end, of histo….

Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you..

There are naive questions, tedious questions, ill-phrased questions, questions put after inadequate self-criticism. But every question is a cry to un….