Planets

Though many other civilizations in the Culture books live on planets, the Culture as it currently exists has little direct connection to planet life. A small number of homeworlds of the founding member species of the Culture are mentioned in passing, and a few hundred human-habitable worlds were colonised (some being terraformed) before the Culture chose to turn towards artificial habitats, preferring to keep the planets it encounters wild. Since then, terraforming has become looked down on by the Culture as inelegant, ecologically problematic and possibly even immoral. Less than one percent of the population of the Culture lives on planets, and many find the very concept a bit bizarre.

This respect is not absolute though; in Consider Phlebas, some Minds suggest testing a new technology on a "spare planet" (knowing that it could be destroyed in an antimatter explosion if unsuccessful). It should be assumed from their normal ethics, that this planet would have been lifeless to start with. It is also quite possible, even probable, that the suggestion was not made in complete seriousness.