The new school motto "Educate yourself, think carefully, discern clearly and practice diligently" comes from "Book of Rites· Doctrine of the Mean". In 1924, when Dr. Sun Yat-sen asked Zou Lu to found Guangdong University, he personally inscribed "Erudition, careful questioning, clear discrimination, and diligent practice" as the school motto. In 1934, the original Sun Yat-sen University, which was built at the address of Hua Gong and Huanong, also used the above 15 words as its school motto. Later, Sun Yat-sen University simplified it into 10 words: "Learn eruditely, inquire carefully, think carefully, discern clearly and practice diligently" Chapter 19 of the Book of Rites·The Doctrine of the Mean has this saying: "Learn eruditely, inquire carefully, think carefully, and understand clearly." Distinguish it and practice it diligently. "This refers to several levels of learning, or several progressive stages. "Erudition" means that in order to learn, you must first hunt extensively and cultivate abundant and vigorous curiosity. When curiosity is lost, The desire to learn will then disappear, and erudition will become impossible. "Bo" also means broadness and tolerance. "Tolerance is great", and then "to love others and to be kind". Therefore, erudition can become the first stage of learning. Beyond this stage, learning is a tree without roots and water without a source. "Interrogation" This is the second stage. If something is not clear, you must inquire to the end and doubt what you have learned. After questioning, you must carefully examine and analyze it through your own ideological activities. Otherwise, what you have learned cannot be used by yourself, which is called "thinking carefully." "Clear debate" is the fourth stage. Learning becomes clearer with more debate. Without debate, the so-called "erudite knowledge" will be mixed, and it will be difficult to distinguish between good and bad. "Practice diligently" is the final stage of learning. Since you have learned something, you must work hard to implement what you have learned, and achieve "the unity of knowledge and action". "Du" means being loyal, down-to-earth, single-minded, and persevering. Only those with clear goals and firm will can truly "act diligently".