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 live at a moment when our relationships to each other, and to all other beings with whom we share this planet, are up for grabs.

It's sometimes easier to reject strong evidence than to admit that we've been wrong, this is information about ourselves worth having.

All civilizations become either spacefaring or extinct.

I would love to believe that when I die I will live again, that some thinking, feeling, remembering part of me will continue.

Religions contradict one another-on small matters, such as whether we should put on a hat or take one off on entering a house of worship, or whether we should eat beef and eschew pork or the other way around, all the way to the most central issues, such as whether there are no gods, one God, or many gods.

You have to know the past to understand the present.