There is a doubt about the value of learning.

"Learning is valuable but doubtful" is Lu Jiuyuan's famous saying. This sentence expresses the importance of asking questions and questioning during the learning process. Lu Jiuyuan was a thinker and educator in the Southern Song Dynasty. His thought advocated "investigating things to gain knowledge" and emphasized that learning requires the acquisition of knowledge through observation and exploration of things. He believes that only by constantly raising questions and doubts can we truly understand and master knowledge, so as to better apply and practice it. This idea had a profound influence on later generations of educators and scholars.