《宋史·列传·卷八十》
从前三院御史经常有二十名，后来被逐渐减少，这是由于执政大臣不想让君主对天下政事的缺失知道得太多。
旧三院御史，常有二十员，而后益衰减，盖执政者不欲主上闻中外之阙失。
There used to be 20 Censors in the three courts, but they were gradually reduced, because the ministers in power did not want the emperor to know too much about the deficiencies of the world's affairs.