In ancient times, the titles of many chapters in the Four Books and Five Classics were the first words of a paragraph.

Yes, because there was no topic at that time.

There is another situation. After the catastrophe of Qin Shihuang's "burning books to bury Confucianism", many ancient books disappeared and few survived. For example, Shangshu was memorized by memory and dictation, and some of it was entrusted by later generations by mistake. For example, Jin Wenshu, Hou Yi Biao and so on.

Take the Analects of Confucius as an example. Take the first two words of a passage.

However, this does not affect the original intention of the article.