《贞观政要·卷三·论封建》
如果取消他的封国，而其先祖的功业还在；如果保留他的封国，而他本人已经罪恶昭彰。
政欲绝之也，则子文之治犹在；政欲留之也，而栾黡之恶已彰。
If we abolish their feudal states, the achievements of their ancestors will be forgotten; if we keep their feudal states, they will themselves be notorious criminals.