...but I also can't prove that mushrooms could not be intergalactic spaceships spying on us.

If I know better than you know what I am up to, it is only because I spend more time with myself than you do.

Cults and prophets proclaiming the imminent end of the world have been with us for several millennia, and it has been another sour sort of fun to ridicule them the morning after, when they discover that their calculations were a little off. But, just as with Marxists, there are some among them who are working hard to "hasten the inevitable," not merely anticipating the End Days with joy in their hearts, but taking political action to bring about the conditions they think are the prerequisites for that occasion.

It is not so much that we, using our brains, spin our yarns, as that our brains, using yarns, spin us.

My faith in the expertise of physicists like Richard Feynman, for instance, permits me to endorse—and, if it comes to it, bet heavily on the truth of—a proposition that I don't understand. So far, my faith is not unlike religious faith, but I am not in the slightest bit motivated to go to my death rather than recant the formulas of physics. Watch: E doesn't equal mc2, it doesn't, it doesn't! I was lying, so there!

I should emphasize this, to keep well-meaning but misguided multiculturalists at bay: the theoretical entities in which these tribal people frankly believe — the gods and other spirits — don't exist. These people are mistaken, and you know it as well as I do. It is possible for highly intelligent people to have a very useful but mistaken theory, and we don't have to pretend otherwise in order to show respect for these people and their ways.

In 50 years - or 20 years, or 200 years - our current epistemic horizon (the Big Bang, roughly) may look as parochial as the horizon Newton had to settle for in his day, but no doubt there will still be good questions whose answers elude us.