《后汉书·列传·杜栾刘李刘谢列传》
刘陶这时在太学游学，上疏说： 我听说人如果没有天地，就不能生活，天地没有人，就无所谓灵。所以皇帝没有人不立，人没有皇帝就不得安宁。
臣闻人非天地无以为生，天地非人无以为灵，是故帝非人不立，人非帝不宁。
Liu Tao was studying at the Imperial University at that time, he drafted a memorial saying: I heard that people cannot live without heaven and earth, and heaven and earth are meaningless without people. That is why the emperor cannot stand without people, and people cannot be at peace without an emperor.