Do all the people on my flist who enjoy science fiction know the Ender series by Orson Scott Card (Ender's Game, Speaker for the Dead, Xenophon, Children of the Mind)? These are four (I think) brilliant books which belong in that very small category of science fiction novels where philosophical speculation and discussions of morality (and penance, and atonement) are at least as important as the spaceships. They're on my bookshelves alongside Asimov's Foundation trilogy, Bradbury's Martian Chronicles, Clarke's Childhood's End, Herbert's Dune novels, Simak's Way Station, and Stapledon's Odd John and Sirius. (Lem probably belongs here, too, but I haven't gotten around to reading him yet.)
Behind the cut there's a little bit about each of the Ender books taken from its back cover. Don't let the fact that Ender's Game has a six-year-old as its protagonist put you off. This is very much a book for adults, as are its sequels. [Note: I've not read any of the "offshoots" as I'll call them, which deal with other characters from the Battle School. The series of four books I'm recommending is complete in and of itself.]
[Special note for vlad_impaler and dominiquelechic: Kat (Ekaterina Cisne do Norte) has a name patterned after the Brazilian/Russian scientists who first appear in Speaker for the Dead. I loved the musicality of their names, and wanted something exotic for this character of mine who is, as you know, on the WA sidelines observing the drama.]
Andrew 'Ender' Wiggin thinks he is playing computer simulated war games at the Battle School; he is, in fact, engaged in something far more desperate. Ender is the result of decades of genetic experimentation, Earth's attempt to make the military genius that the planet needs in its all-out war with an alien enemy.
Is Ender the general Earth needs? The only way to find out is to throw the child into ever harsher training, to chip away and find the diamond inside, or destroy him utterly. Ender Wiggin is six years old when it begins. He will grow up fast.
But Ender is not the only result of the experiment. The war with the Buggers has been raging for a hundred years, and the quest for the perfect general has been underway for almost as long. Ender's two older siblings, Peter and Valentine, are every bit as unusual as he is, but in very different ways.
Between the three of them lie the abilities to remake a world. If, that is, the world survives. [Argh! The grammar nazi in me shudders and points out that "between" is used for two, and "among" is used for three or more.]
Speaker for the Dead:
Three thousand planet-bound years have fled since Ender Wiggin won humanity's war with the Buggers by totally destroying them. Ender remains young -- traveling the stars at relativistic speeds, a hundred years or more might pass while he experiences a month-long voyage. In three thousand years, his books The Hive Queen and The Hegemon have become holy writ, and the name of Ender anathema; he is the Xenocide, the one who killed an entire race of thinking, feeling beings, killed the only other sentient race humankind had found in all the galazy.
The only ones, that is, until the planet called Lusitania was discovered and colonized. This discovery was seen as a gift to humanity, a chance to redeem the destruction of the Buggers. This time, the Starways Congress vowed, there would be no tragic misunderstanding leading to war.
But once again men would die, killed by the aliens in a rite no one understands. Ender, now known only as the Speaker for the Dead, comes to Lusitania to Speak for those who have died -- and discovers that in order to tell the truth about them, he must unravel the secrets of Lusitania.
The war for the survival of the planet Lusitania will be fought in the heart of a child named Gloriously Bright ["Qing-jao", Jen and Tavi].
On Lusitania, Ender found a world where humans and pequeninos and the Hive Queen could all live together; where three very different intelligent species could find common ground. Or so he thought.
Lusitania also harbors the descolada, a virus that kills all humans it infects, but which the pequeninos require in order to become adults. The Starways Congress so fears the effect of the descolada, should it escape from Lusitania, that they have ordered the destruction of the entire planet and all who live there. The Fleet is on its way, and a second xenocide seems inevitable.
Children of the Mind:
The planet Lusitania is home to three sentient species: the Pequeninos, a large colony of humans, and the Hive Queen, who was brought there by Ender Wiggin. But now, once again, the human race has grown fearful; the Starways Congress has gathered a fleet to destroy Lusitania.
Ender's oldest friend, Jane, an evolved computer intelligence, can save the three sentient species of Lusitania. She has learned how to take ships outside the universe, and then instantly back to a different world, abolishing the light-speed limit. But it takes all the processing power available to her, and the Starways Congress is shutting down the network of computers in which she lives, world by world.
Soon Jane will not be able to move the ships. Ender's children must save her if they are to save themselves.