"The Left Hand of Darkness" by Ursula Le Guin

This is chronologically the fourth book in the Hainish cycle and happens after the Shing are defeated (somehow) and the Ekumen of 83 worlds is formed. The book details the adventures, problems and successes of Genry Ai, a 'mobile' of the Ekumen, and an envoy to Gethen, to try persuade the governments to join the Ekumen. The gethenians are hermaphrodites which are sexually inactive for most of the lunar month, while only being activated for a few days each month, which period they call Kemmer, and when through hormonal negotiations of willing partners, one becomes female while the other male. Every person on Gethen has a womb and menstrual cycle, is able to both father children and bear them to birth.

Genly is amazed by the social consequences of not having sexes. One is that war is virtually unknown, which Genly thinks is because war comes out of male sexual frustration. Genly is black male from earth, as in the future the white race has disappeared, and the black and yellow races have merged into a brown-black one. He is considered a 'pervert' on Gethen because they cannot understand how can one be sexually capable all the time and still be normal. The Gethenians consider all the other planets and races perverts and don't want much to do with them, if they believe they exist at all. The situation is further complicated by the two main nations on Gethen, Karhaid and Orgoreyn, one being a kingdom and the other a communist-like oligarchy, are bitter enemies and both want the other to take the risk first to make contact with the alien federation. Both countries are on a technological level of approximately late 20 century Earth, but have arrived to that level not through industrial revolution, but through a very slow evolutionary path, as nobody hurries for anything on Gethen.

Genly becomes persona non grata after his main friend Estrevan, the prime minister of Karhaid, is exiled because of political power play, and goes to Orgoreyn, where at first he's accepted with great honors, just to be thrown in a labor camp in the north to die of exhaustion afterward. Estrevan, who escaped to Orgoreyn too, helps him escape and they hike over the huge northern glacier area to go back to Karhaid and form a very strong personal bond. Estrevan is killed when they arrive in Karhaid, but Genly is received by the king and Karhaid enters the Ekumen, which was the goal of Genly's mission.

The book is obviously feminist fiction and tries very hard to dissect the different ways women are subjugated in our own society, by exploring the different traits that Gethenians developed. This detracts from the enjoyment of the book, since at times seems too didactic, but provides for the very in-depth analysis of the Gethenian society and interpersonal relationships, and artifacts like 'shiftgrethor' which can be translated as personal prestige or personal shadow. The possibility and meaningfullnes of divination is also explored in the religion of karhaid and their rituals. Love between sexes, whether same, different or non-existent, is explored at depth and the reader is gently introduced to the concept that sexes are irrelevant for love, but only the human beings matter.

One very annoying and very unrealistic thing on which Le Guin obstinately insists, is that the Ekumen, or any very advanced civilization, will send its envoy(s) alone and completely unprotected, on the mercy of the primitive and sometimes very different occupants of the new planet. This is obviously an inheritance from Le Guin's father who was an antropoligist and vocal for protection of the less-developed peoples around the world whose societies are destroyed when the white men (usually) came and introduced their own society and technology. This she calls 'cultural embargo', however it is preposterous to think any self-respecting star-spanning culture would throw some of its own people (highly trained and intelligent) into the jaws of the lions with no protection, to be imprisoned, tortured, even murdered. That would be extremely unethical for the star society itself towards its own people (i.e. it would require some kind of benevolent kamikaze indoctrination), and although the natives definitely should be protected and introduced gradually to the new society, the first envoys will always be sent with enough power and protection to absolutely guarantee their life and well being - at the minimum.

On the whole, extremely well written book, emotional, intelligent and interesting read.