I have read an article written by the side called "Huang Huang Shangyao". This paper focuses on Cai Yuanpei's actions during his tenure as president of Peking University in the 1920s, which is admirable and loyal to academics. There is a passage about Cai Yuanpei recruiting Liang Shuming as a lecturer because of On Doubt and Determinism. You can find this article (Huang Huang Shang Yao), and you will be deeply impressed by Cai's thoughts and concepts.

In addition, in the first volume of "Crossing the South and Returning to the North" I read some time ago, there is a similar example. A person is not only named. Also in the 1920s (I can't remember), Tsinghua formed a powerful group of lecturers, known as "the five famous teachers in Tsinghua" (Wu Mi, Wang Guowei, Zhao Yuanren, Chen Yinke and Liang Qichao). Among them, only Zhao Yuanren has a degree certificate, and the other four have no officially certified academic qualifications. They can teach only because they are knowledgeable. Chen Yinque studied abroad for several years.

I hope I can help you!