The surface of the Earth is the shore of the cosmic ocean.

Avoidable human misery is more often caused not so much by stupidity as by ignorance, particularly our ignorance about ourselves.

All of us cherish our beliefs. They are, to a degree, self-defining. When someone comes along who challenges our belief system as insufficiently well-based - or who, like Socrates, merely asks embarrassing questions that we haven't thought of, or demonstrates that we've swept key underlying assumptions under the rug - it becomes much more than a search for knowledge. It feels like a personal assault.

We invest far off places with a certain romance... Long summers, mild winters, rich harvests, plentiful game; none of them lasts for ever. Your own life, or your bands, or even your species - might be owed to a restless few, drawn by a craving they can hardly articulate or understand, to undiscovered lands, and new worlds.

Too much openness and you accept every notion, idea, and hypothesis-which is tantamount to knowing nothing. Too much skepticism-especially rejection of new ideas before they are adequately tested-and you're not only unpleasantly grumpy, but also closed to the advance of science. A judicious mix is what we need.

Philosophers and scientists confidently offer up traits said to be uniquely human, and the monkeys and apes casually knock them down -- toppling the pretension that humans constitute some sort of biological aristocracy among the beings on Earth.

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