《论衡·卷九·问孔篇》
不能全对，当时的人却不懂得反驳；有的虽正确，但意思隐晦，难得明白，当时的人也不晓得去追问。
不能皆是，时人不知难；或是，而意沉难见，时人不知问。
They could not be right about everything, but their contemporaries did not know how to refute them; and although some things they said were right, their meaning was obscure and difficult to understand, so their contemporaries did not know how to ask questions about them.