Also the Galactic Empire as an anti-scientific hellhole with secret police surveillance.
Witness good old Hari Seldon unveiling his plans on Trantor:
It was not a large office, but it was quite spy-proof and quite undetectably so. Spy-beams trained upon it received neither a suspicious silence nor an even more suspicious static. They received, rather, a conversation constructed at random out of a vast stock of innocuous phrases in various tones and voices.
[Seldon] put his fingers on a certain spot on his desk and a small section of the wall behind him slid aside. Only his own fingers could have done so, since only his particular print-pattern could have activated the scanner beneath.
[…]
“You will find several microfilms inside,” said Seldon. “Take the one marked with the letter T.”
Gaal did so and waited while Seldon fixed it within the projector and handed the young man a pair of eyepieces. Gaal adjusted them, and watched the film unroll before his eyes.
Everyone is entitled to their own readership of Banks. I'm not saying mine is the one and only. But the Culture is supposed to be a background character, even if Banks spends a lot of time in the later novels "explaining" it. But if the reader only focusses on the lore, they'll miss the quite good characters and psychology that Banks was good at too.
My personal favorite is Use of Weapons, where the focus is on the people doing the Culture's dirty work. In one scene, Zakalwe
spoiler
spends an inordinate time trying to protect a useless aristocracy from being wiped out by a revolution, only to find out his side was meant to lose for some inscrutable Mind-directed reason. This kind of shit happens all the time to him, and as he's basically a deeply traumatized individual he's able to keep doing it.In Look to Windward
spoiler
Contact goes too far along the path of optimizing "help backwards civilization" and manages to create a genocidal civil war. The survivors decide to try to destroy a Mind (and the Orbital it's managing), and you know, you kind of get why.