The Culture books tend to star people on the margins of the eponymous Culture: disaffected citizens, spies, mercenaries, people from other involved (and usually more conservative) civilizations. They almost always have serious character flaws (a number of them are out-and-out assholes) and while character development does occur, generally toward Culture values, it's not usually dramatic. On the other hand, the culture itself, and the AI entities that run it, are presented as having few to no flaws from the narrative's perspective. While the characters are often critical of it, it's fairly clear where the author's sympathies lie.

They're not rationalist fiction in the sense that Methods is, or even in the sense that Asimov's Foundation books are. They do make for a decent stab at eutopia from a socially liberal soft-transhumanist perspective, though not an especially radical one.