The vast distances that separate the stars are providential. Beings and worlds are quarantined from one another. The quarantine is lifted only for those with sufficient self-knowledge and judgment to have safely traveled from star to star.

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.

All over the world there are enormous numbers of smart, even gifted, people who harbor a passion for science. But that passion is unrequited. Surveys suggest that some 95% of Americans are "scientifically illiterate." That's...the same fraction...of slaves who were illiterate before the Civil War.

Sailors on a becalmed sea, we sense the stirring of a breeze.

For myself, I like a universe that, includes much that is unknown and, at the same time, much that is knowable. A universe in which everything is known would be static and dull, as boring as the heaven of some weak-minded theologians. A universe that is unknowable is no fit place for a thinking being. The ideal universe for us is one very much like the universe we inhabit. And I would guess that this is not really much of a coincidence.

Writing is perhaps the greatest of human inventions, binding together people who never knew each other, citizens of distant epochs. Books break the shackles of time. A book is proof that humans are capable of magic.

Books are like seeds. They can lie dormant for centuries and then flower in the most unpromising soil.