《旧唐书》卷一六五《柳公权传》对唐代大书法家柳公权的生平事迹有这样的记述:“公权字诚悬。幼嗜学,十二能为辞赋。元和初,进士擢第,释褐秘书省校书郎。李听镇夏州辟为掌书记。穆宗即位,入奏事,帝召见,谓公权曰:‘我于佛寺见卿笔迹,思之久矣。’即日拜右拾遗,充翰林侍书学士,迁右补阙、司封员外郎。穆宗政僻,尝问公权笔何尽善,对曰:‘用笔在心,心正则笔正。’上改容,知其笔谏也。”可以说“用笔在心,心正则笔正。”这段话既是柳公 “The old Tang book,” Volume 165 “Liu Gong Quan Zhuan” on the Tang Dynasty calligrapher Liu Gongquan’s deeds have such a account: “Public power word Cheng hanging. Young Philharmonic, twelve for the Fu. Yuan and early, Jinshi 擢 the first release of the secretary of the provincial school Shu Lang. Listen to the town of Xiazhou governor Palm secretary. Ascended the throne, into the play, Emperor summoned, said the public authority said: ’I see the pen in the Buddhist temple, think for a long time. Right now thanks to the right pick up, filling Hanlin bachelor, moved to the right complement Que, Secretary Feng Wai Wa Lang. Muzong regime secluded, to ask the public pen how to make good, on the said: ’Pen in mind, heart is positive pen’. , Know its pen remonstrance also. ”Can say “ in the heart with a pen, heart is pen positive. ”This passage is both Liu Gong