If it’s difficult to establish the truth, there’s a reason: 37 years after the Cultural Revolution, it’s still impossible to research, discuss or publish about it freely in China. Censorship is harsh — there are well-known people who have much to hide about what they did, some say. Guilt lingers. The result is confusion, despite a deep well of personal memory (memory again!). The field is open for denial, exaggeration and shame. “Proof” is often merely recollection, Ms. McCarthy’s unreliable friend.

Is Ms. Fu telling the truth, but people just don’t know it? Or are “nightingales” singing in a self-dramatizing narrative? Until China opens its archives and permits open debate, we won’t know. Not for sure. Because even “experts” on China are often wrong. The facts just aren’t available.