《论衡·卷十六·讲瑞篇》
圣人难以识别，像桓君山、杨子云这样智慧才能很高的人，尚且不能识别，世儒仅有平凡的才智，死抱住圣人骨相没有差别这种见解，见了圣人不能识别，可以保证必然是这样。
夫圣人难知，知能之美若桓、扬者，尚复不能知。世儒怀庸庸之知，赍无异之议，见圣不能知，可保必也。
Sages are hard to recognize. Even though wise and talented people like Huan Junsan and Yang Ziyun couldn't recognize them, so Confucian scholars who only have ordinary intelligence and stubbornly hold on to the idea that distinguishing a sage only depends on the bone structure, will definitely not be able to recognize a sage even if they meet one.