All civilizations become either spacefaring or extinct.

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

The Bill of Rights decoupled religion from the state, in part because so many religions were steeped in an absolutist frame of mind - each convinced that it alone had a monopoly on the truth and therefore eager for the state to impose this truth on others.

I can find in my undergraduate classes, bright students who do not know that the stars rise and set at night, or even that the Sun is a star.

Even Johannes Kepler, Isaac Newton, Charles Darwin, Gregor Mendel, and Albert Einstein made serious mistakes. But the scientific enterprise arranges things so that teamwork prevails: What one of us, even the most brilliant among us, misses, another of us, even someone much less celebrated and capable, may detect and rectify.

UFOs: The reliable cases are uninteresting and in the interesting cases are unreliable.

Preserve and cherish the pale blue dot, the only home we've ever known.