Many of the series' protagonists are humanoids who have chosen to work for the Culture's diplomatic or espionage organs, and interact with other civilisations whose citizens act under different ideologies, morals, and technologies.
The Culture's citizens have been genetically enhanced to live for centuries and have modified mental control over their physiology, including the ability to introduce a variety of psychoactive drugs into their systems, change biological sex, or switch off pain at will.
As mentioned in The Player of Games, the Culture does have the occasional "crime of passion" (as described by an Azadian) and the punishment was to be "slap-droned", or to have a drone assigned to follow the offender and "make sure [they] don't do it again".
While the enforcement in theory could lead to a Big Brother-style surveillance society, in practice social convention among the Minds prohibits them from watching, or interfering in, citizens' lives unless requested, or unless they perceive severe risk.
[5] This gives some measure of privacy and protection; though the very nature of Culture society would, strictly speaking, make keeping secrets irrelevant: most of them would be considered neither shameful nor criminal.
[6] The Culture is a posthuman society, which originally arose when seven or eight roughly humanoid space-faring species coalesced into a quasi-collective (a group-civilisation) ultimately consisting of approximately thirty trillion (short scale) sentient and sapient beings (this includes artificial intelligences).
Also, except for some mentions about a vote over the Idiran-Culture War, and the existence of a very small number of "Referrers" (humans of especially acute reasoning), few biological entities are ever described as being involved in any high-level decisions.
As described there and in Player of Games, a Culture citizen who becomes dysfunctional enough to pose a serious nuisance or threat to others would be offered (voluntary) psychological adjustment therapy and might potentially find themself under constant (non-voluntary) oversight by representatives of the local Mind.
In extreme cases, as described in Use of Weapons and Surface Detail, dangerous individuals have been known to be assigned a "slap-drone", a robotic follower who ensures that the person in question doesn't continue to endanger the safety of others.
Indeed, some are eventually deemed psychologically unsuitable as agents (for example as Mawhrin-Skel notes about itself in The Player of Games) and must choose either mental reprofiling or demilitarisation and discharge from Special Circumstances.
Unsurprisingly, given their duties, Minds are tremendously powerful: capable of running all of the functions of a ship or habitat, while holding potentially billions of simultaneous conversations with the citizens that live aboard them.
In the Culture universe, Minds have become an indispensable part of the prevailing society, enabling much of its post-scarcity amenities by planning and automating societal functions, and by handling day-to-day administration with mere fractions of their mental power.
Their capacities only allow them to be considered equivalent to what are now known as AI Cores, small (in the literal physical sense) Artificial intelligences used in shuttles, trans-light modules, Drones, and other machines not large enough for a full scale Mind.
In Consider Phlebas, a typical Mind is described as a mirror-like ellipsoid of several dozen cubic metres, but weighing many thousands of tons, due to the fact that it is made up of hyper-dense matter.
Banks has evolved a (self-confessedly) technobabble system of theoretical physics to describe the ships' acceleration and travel, using such concepts as "infraspace" and "ultraspace" and an "energy grid" between universes (from which the warp engines "push off" to achieve momentum).
The Culture, and other civilisations in Banks' universe, are described as living in these various, often constructed habitats: These are vast, brown dwarf-sized bubbles of atmosphere enclosed by force fields, and (presumably) set up by an ancient advanced race at least one and a half billion years ago (see: Look to Windward).
Citizens of the Culture live there only very occasionally as guests, usually to study the complex ecosystem of the airspheres and the dominant life-forms: the "dirigible behemothaurs" and "gigalithine lenticular entities", which may be described as inscrutable, ancient intelligences looking similar to a cross between gigantic blimps and whales.
About 4000 were built millions of years ago as vast machines intended to cast a forcefield around the whole of the galaxy for unknown purposes; less than half of those remain at the time of Matter, many having been destroyed by a departed species known as the Iln.
They are also contrasted with what some Culture people loosely refer to as "barbarians", societies of intelligent beings which lack the technical capacity to know about or take a serious role in their interstellar neighbourhood.
These are entities that exist to convert as much of the universe as possible into more of themselves; most typically these are technological in nature, resembling more sophisticated forms of grey goo, but the term can be applied to cultures that are sufficiently single-minded in their devotion to mass conquest, control, and colonisation.
The usage of the term "hegemonising swarm" in this context is considered derisive in the Culture and among other Involved and is used to indicate their low regard for those with these ambitions by comparing their behaviour to that of mindless self-replicating technology.
Non-Contact citizens are apparently not prevented from travelling or interacting with other civilisations, though the effort and potential danger involved in doing so alone makes it much more commonly the case for Culture people simply to join Contact if they long to "see the world".
It is shown in Consider Phlebas that actual decisions to go to war (as opposed to purely defensive actions) are based on a vote of all Culture citizens, presumably after vigorous discussion within the whole society.
The inner workings of The Culture are not especially described in detail though it is shown that the society is populated by an empowered, educated and augmented citizenry in a direct democracy or highly democratic and transparent system of self-governance.
[23] The events of Use of Weapons are an example of just how dirty Special Circumstances will play in order to get their way and the conspiracy at the heart of the plot of Excession demonstrates how at least some Minds are prepared to risk killing sentient beings when they conclude that these actions are beneficial for the long term good.
It is highly egalitarian; the liberty of the individual is its most important value; and all actions and decisions are expected to be determined according to a standard of reasonability and sociability inculcated into all people through a progressive system of education.
Contact, the group that handles these issues, and Special Circumstances, its secret service division, can employ only those on whose talents and emotional stability it can rely, and may even reject self-aware drones built for its purposes that fail to meet its requirements.
Contact and Special Circumstances may suppress or delay the release of information, for example to avoid creating public pressure for actions they consider imprudent or to prevent other civilisations from exploiting certain situations.
In one incident during the Culture–Idiran War, they strive to avoid offending a civilisation so advanced that it has disengaged from Galactic politics, and note that this hyper-advanced society is not a threat to either the welfare or the values of the Culture.
This sort of stuff has been going on for decades and mainstream society is beginning to catch up to the implications of artificial intelligence.In a 2002 interview with Science Fiction Weekly magazine, when asked: Excession is particularly popular because of its copious detail concerning the Ships and Minds of the Culture, its great AIs: their outrageous names, their dangerous senses of humour.