From Gardner Dozois' introduction: The battle of science against superstition is still going on, as is the battle to not have to think only what somebody else thinks is okay for you to think. In fact, in a society where more people believe in angels than believe in evolution, that battle may be more critical than ever.

One of the major battlefields of that war is science fiction, one of the few forms of literature where rationality, skepticism, the knowledge of the inevitability of change, and the idea that wide-ranging freedom of thought and unfettered imagination and curiosity are good things are the default positions, taken for granted by most of its authors.

Until some new Inquisition, motivated by ignorance, intolerance, and fear, forces its writers to go underground and mutter "It still moves!" to each other in hiding, science fiction provides one of the few places in modern letters where the battle between science and superstition is openly discussed and debated, and that makes those who write it, as well as those brave characters they write about, embroiled in the age-old struggle to prevent the control of the human mind and the suppression of the human spirit, "Galileo's Children" in a very real way indeed.

The anthology that follows takes us to many different battlefields in that struggle, from the past to the present to the future, to worlds that never were and never will be to worlds deep in space that someday may come to pass, and introduces us to many different warriors, male and female, rich and poor, young and old, who, in their different ways--some quietly, some defiantly, some reluctantly-fight the kind of battles that we ourselves might someday have to fight if we want our children and our grandchildren to be allowed to read these words. Stories by: Arthur C Clarke Ursula K Le Guin Greg Egan George R R Martin Mike Resnick Robert Silverberg and others