Ashil to Borlú, about how vital the mental gymnastics are to living in The City:

“Nowhere else works like the cities”, he said. “It’s not just us keeping them apart. It’s everyone in Besźel and everyone in Ul Qoma. Every minute, every day. We’re only the last ditch: it’s everyone in the cities who does most of the work. It works because you don’t blink. That’s why unseeing and I sensing are so vital. No one can admit it doesn’t work. So if you don’t admit it, it does. But if you breach, even if it’s not your fault, for more than the shortest time… you can’t come back from that.”

He’s talking about people in the cities not acknowledging each other though they literally walk past each other, but it could just as easily be about any systemic structure set up to maintain an artificial boundary. Racism, sexism, classism, religious differences, homelessness: wherever there is a dividing line that depends on both sides not acknowledging the other, learning to see the differences so that you do not see them. Once you stop unseeing the differences, once you perceive reality, you can’t go back. The genius of Miéville’s setup is those who grow up in it automatically give cover to the boundary keepers who do unsee by not seeing them. And if the citizen does unsee, they are given a choice: unspeakable disappearance, or remain and become complicit in its structure. It’s not hard to see examples in reality, of those boundary crossers who disappear or become the enforcers, for various reasons.

This is a truly spectacular book that gives voice to a difficult to perceive and talk about subject, merely by explicating and showing in relief how it works in an extraordinary setting.