Our children long for realistic maps of the future that they can be proud of. Where are the cartographers of human purpose?

When you make the finding yourself - even if you're the last person on Earth to see the light - you'll never forget it.

Observation: I can't see a thing. Conclusion: Dinosaurs.

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.

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.

I worry that, especially as the Millennium edges nearer, pseudo-science and superstition will seem year by year more tempting, the siren song of unreason more sonorous and attractive.

The Earth is a very small stage in a vast cosmic arena.