The Left Hand of Darkness is set in the fictional Hainish universe, which Le Guin introduced in her first novel Rocannon's World, published in 1966. In this fictional history, human beings did not evolve on Earth, but on Hain. The people of Hain colonized many neighboring planetary systems, including Terra (Earth) and Gethen, possibly a million years before the setting of the novels. Some of the groups that "seeded" each planet were the subjects of genetic experiments, including on Gethen.[20] The planets subsequently lost contact with each other, for reasons that Le Guin does not explain.[22] Le Guin does not narrate the entire history of the Hainish universe at once, instead letting readers piece it together from various works.[23]
The novels and other fictional works set in the Hainish universe recount the efforts to re-establish a galactic civilization. Explorers from Hain as well as other planets use interstellar ships traveling nearly as fast as light. These take years to travel between planetary systems, although the journey is shortened for the travelers due to relativistic time dilation, as well as through instantaneous interstellar communication using the ansible, a device invented during the events described in The Dispossessed.[22] This galactic civilization is known as the "League of All Worlds" in works set earlier in the chronology of the series, and has been reconstructed as the "Ekumen" by the time the events in The Left Hand of Darkness take place.[22] During the events of the novel, the Ekumen is a union of 83 worlds, with some common laws.[23] At least two "thought experiments" are used in each novel. The first is the idea that all humanoid species had a common origin; they are all depicted as descendants of the original Hainish colonizers. The second idea is unique to each novel.[20]
The Left Hand of Darkness takes place many centuries in the future—no date is given in the book itself. Reviewers have suggested the year 4870 AD, based on extrapolation of events in other works, and commentary on her writing by Le Guin.[4] The protagonist of the novel, the envoy Genly Ai, is on a planet called Winter ("Gethen" in the language of its own people) to convince the citizens to join the Ekumen. Winter is, as its name indicates, a planet that is always cold.[24]
The inhabitants of Gethen are ambisexual humans; for twenty-four days (a period called somer in Karhidish, a Gethenian language) of each twenty-six-day lunar cycle, they are sexually latent androgynes. They only adopt sexual attributes once a month, during a period of sexual receptiveness and high fertility, called kemmer. During kemmer they become sexually male or female, with no predisposition towards either,[25] although which sex they adopt can depend on context and relationships.[7] Throughout the novel Gethenians are described as "he", whatever their role in kemmer. This absence of fixed gender characteristics led Le Guin to portray Gethen as a society without war, and also without sexuality as a continuous factor in social relationships.[25][24] On Gethen, every individual takes part in the "burden and privilege" of raising children, and rape and seduction are almost absent.[24]
