Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us - then, habits of thought familiar from ages past reach for the controls.

Probably a dozen times since their death I've heard my mother or father, in an ordinary conversational tone of voice, call my name. They had called my name often during my life with them ... It doesn't seem strange to me.

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.

The wind whips through the canyons of the American Southwest, and there is no one to hear it but us - a reminder of the 40,000 generations of thinking men and women who preceded us, about whom we know almost nothing, upon whom our civilization is based.

Before we invented civilization our ancestors lived mainly in the open out under the sky. Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.

The Big Bang is our modern scientific creation myth. It comes from the same human need to solve the cosmological riddle [Where did the universe come from?]

Books permit us to voyage through time, to tap the wisdom of our ancestors.