Does the current emperor have no shortcomings?
Of course, he has a lot, otherwise, Wei Zhi wouldn't keep scolding him every now and then.
To set a good example for the emperor, Wei Zhi keeps no more than five servants at home, though his position rivals that of a Prime Minister, yet he lives more frugally than an average rich family.
But Confucianism teaches that a son shouldn't criticize his father, so Libationer Kong would never use the current emperor or the late emperor as examples when teaching the Crown Prince the Classic of Filial Piety.
He mostly uses the reigns of the Han Dynasty emperors Wen, Jing, and Wu, or even further back, discussing the Warring States, the Spring and Autumn period, and the governance of the Two Zhou dynasties to explain the Classic of Filial Piety.
If the Crown Prince were an ordinary prince, he would obediently attend classes, perhaps even forming a respectful and filial relationship with the Emperor.
