《贞观政要·卷四·规谏太子》
学习儒学，可以了解政事的得失，也可以提高自身的修养；因为知书达理而欣喜，可以用来识辨愚蠢的人；因为不知道典故而惭愧，需要去请教有学问的长者。
咨政理之美恶，亦文身之黼藻。庶有择于愚夫，惭乞言于遗老。
Study Confucianism, understand the gains and losses of political affairs, and improve your own cultivation. Because of your knowledge and understanding, you can be happy, and because of your ignorance, you can ask for help from learned elders.