 When the worthies and sages wrote their works, they used their thoughts to make a detailed investigation of things. We cannot say that they completely attained the truth (about everything) even then. Given this, how could it possibly be that their everyday and idle statements are completely true? These statements cannot all be true, but the people of today don’t know how to challenge them. Or if some of these statements are true and the ideas imparted are unclear and hard to make out, the people of today do not know how to question them. (Lunheng 28.1, author’s translation)