In the speech sound wave, one word runs into the next seamlessly; there are no little silences between spoken words the way there are white spaces between written words. We simply hallucinate word boundaries when we reach the end of a stretch of sound that matches some entry in our mental dictionary.

What a dull universe it would be if everything in it conformed to our expectations, if it held nothing to surprise or baffle us or confound our common sense. A century ago no one foresaw the existence of black holes, an expanding universe, oceans on Jupiter's moons, or DNA. What could be more enriching than to know that we share a common origin with all living things, that we are kin to chimpanzees, redwoods and mollusks? And isn't it a source of wonder to realize that the iron in our blood and the calcium in our bones were created in the bellies of supernovas?

The theory that religion is a force for peace, often heard among the religious right and its allies today, does not fit the facts of history.

Economic libertarians and Christian evangelicals, united by their common enemy, are strange bedfellows in today's Republican party, just as the two Georges - the archconservative Wallace and the uberliberal McGovern - found themselves in the same Democratic Party in 1972.

We are all members of the same flawed species. Putting our moral vision into practice means imposing our will on others. The human lust for power and esteem, coupled with its vulnerability to self-deception and self-righteousness, makes that an invitation to a calamity, all the worse when the power is directed at a goal as quixotic as eradicating human self-interest.

I think that metaphor really is a key to explaining thought and language. The human mind comes equipped with an ability to penetrate the cladding of sensory appearance and discern the abstract construction underneath - not always on demand, and not infallibly, but often enough and insightfully enough to shape the human condition. Our powers of analogy allow us to apply ancient neural structures to newfound subject matter, to discover hidden laws and systems in nature, and not least, to amplify the expressive power of language itself.

Effective education may also require co-opting old faculties to deal with new demands. . . Because much of the content of education is not cognitively natural, the process of mastering it may not always be easy and pleasant, notwithstanding the mantra that learning is fun.