Much of Le Guin's science fiction places a strong emphasis on the
social sciences, including
sociology and
anthropology, thus placing it in the subcategory known as
soft science fiction. Her writing often makes use of unusual
alien cultures to convey a message about our own culture; one example is the exploration of
sexual identity through the
hermaphroditic race in
The Left Hand of Darkness, which forms an important limb in the canon of
feminist science fiction, and additionally societal/anthropological/historical assumptions that transcend feminism are examined brilliantly. Her works also make strong ecological statements as well.
A number of Le Guin's science fiction works, including her award-winning novels
The Dispossessed and
The Left Hand of Darkness, are set in a future, post-Imperial galactic civilization loosely connected by a co-operative body known as the
Ekumen. The Ekumen is very specifically not in any sense a governing body, but rather a conduit for the exchange of information, goods, and mutual cultural understanding. Novels such as
The Left Hand of Darkness and
The Telling deal with the consequences of the arrival of Ekumen envoys (known as "mobiles") on remote planets and the
culture shock that ensues.
Le Guin creates believable worlds populated by strongly sympathetic characters (regardless of whether they are technically 'human'). Le Guin's worlds are made believable by the attention she pays to the ordinary actions and transactions of everyday life. For example in '
Tehanu' it is central to the story that the main characters are concerned with the everyday business of looking after animals, tending gardens and doing domestic chores. Primarily, her works can be seen as anthropological. They examine what humans do on Earth or off. Her interactions between characters are incredibly sympathetic to human expression from the myriad "un-Earthly" perspectives she creates, and explore political and cultural themes. Le Guin has also written fiction set much closer to home; many of her short stories are set in our world in the present or the near future.
A notable feature of her conception that sets her work apart from much of mainstream 'hard' science fiction is that neither the old Empire nor the Ekumen possesses traditional
faster-than-light travel (the Ekumen are developing "churten" technology, a form of instantaneous travel), although the politically progressive Ekumen thrives where the old Empire has failed mainly because it possesses a means of instantaneous interstellar communication, through a device called the
ansible, the invention and consequences of which address the main plot of many stories of the Ekumen. "Churten" technology's conception is covered in the novel
The Dispossessed, and it's development on Hain and O explored in the stories "The Shobies' Story," "Dancing to Ganam," and "Another Story or A Fisherman of the Inland Sea" from
A Fisherman of the Inland Sea. "Churten" technology's practical use, however, becomes complicated because with it the normal laws of time and space become entwined with human consciousness. In a "churten" field, reality itself warps as consciousness perceives it in a way that makes it very difficult to travel easily instantaneously throughout the universe without consequence to time and perception. The only practical means of instantaneous interstellar travel is through the non-material
ansible message transmissions, which play a key role in most of the
Hainish Cycle works.
A remarkable thematic element to the
Hainish Cycle novels and stories is in relation to the Ekumen's "Mobiles," who give up their connections to their home planets in order to travel in time-dilation (a few days pass for them on board their space ships while decades pass on both the worlds they are leaving behind and on the worlds they are heading towards). Generations pass where they left and are traveling to as they travel, their loved ones long gone back home when they arrive. This dynamic of loneliness creates an incredible pathos for the author's characters (often the protagonist), as they deal with leaving behind all they know and cultures they often do not expect to arrive to.
In this loose background scenario, the human species originated on the planet
Hain in the distant past, near the
galactic center. A Galactic Empire had expanded far across the galaxy over many millennia but, because it lacked
faster-than-light (FTL) travel or communication, the Empire was finally stretched beyond its limits by the vast distances involved and it collapsed catastrophically. Thousands of years passed, during which time the populations of many outlying planets became so isolated from the central galactic civilization that they lost all knowledge of their origins, reverting to more archaic forms of civilization and technology, and in some cases developing significant evolutionary differences.