Liu Gongquan did not leave many deeds in politics, but one thing has always been talked about by people. Liu Gongquan was the top scholar in the imperial examination and experienced seven emperors. He is a big official with a smooth career and devoted his life to calligraphy. When Mu Zong was in office, there was an anecdote about him: "Mu Zong was eccentric in politics, and he tried to ask if the pen was good. He said: "with a pen in your heart, your heart is right." Change your face, know your pen and know your words. " (Old Tang Book)

This is the widely circulated story of Liu Gongquan's "remonstrance". "Correct mind and correct pen" is a famous saying that Liu Gongquan left the world with the deepest memory.