The Culture series is a science fiction series written by Scottish author Iain M. Banks. The stories center on the Culture, a utopian society of humanoids, aliens, and very advanced artificial intelligences living in semi-anarchist habitats spread across the post-material-scarcity Milky Way galaxy. The main theme of the novels is the dilemmas that an idealistic hyperpower faces in dealing with civilisations that do not share its ideals, and whose behaviour it sometimes finds repulsive. In some of the stories, action takes place mainly in non-Culture environments, and the leading characters are often on the fringes of, or non-members of, the Culture, sometimes acting as agents of Culture plans to civilise the galaxy.