Note that the distinction between classic department and history department is not simple, and history belongs to history.

There are strict rules, the history department is basically the so-called official history, and the twenty-fourth history is headed by historical records. The previous Shangshu and Chunqiu were also about history, but they could not be included.

Once the Four Books and Five Classics are fixed, they cannot be changed. It is meaningless to ask why these books are other.