Source: Chapter 20 of The Doctrine of the Mean.
"erudition, interrogation, deep thinking, discernment and persistence" is not only a one-way order, but also a process of backward advancement and circular progression: after "learning and speculation", it is necessary to present, verify, advance and practice; After "practice", we should reflect on "wisdom", learn, improve and make progress.
This is what Xia Zi said: "Being an official is the best way to learn, and learning is the best way to be an official". We often say that "learning to be excellent is to be an official". After learning written kung fu, we will devote ourselves to the official career and serve the motherland; In fact, it is also necessary to "learn for the official." Being in the official career and serving the country, we need to constantly learn and improve, and meet Si Qi constantly.
On the one hand, apply what you have learned; On the other hand, it is used to promote learning; Learning and use learn from each other, and learning is endless. This virtuous circle is the significance of advocating "study life" and "lifelong learning" now.
Extended data
"Be knowledgeable, interrogate, think carefully, distinguish clearly and stick to it", a famous saying in The Doctrine of the Mean, is often regarded as an inspirational motto. For example, the motto of Sun Yat-sen University is: erudite, interrogative, thoughtful, discerning and persistent.
This sentence clearly points out several important steps in the process from "learning" to "learning": erudition, erudition and extensive learning, which is the process of absorbing knowledge; Interrogation, careful questioning and in-depth questioning are the process of answering questions; Seriously think, seriously think, seriously think, this is the process of selection and digestion; Distinguish clearly, distinguish clearly, distinguish clearly, this is the process of choosing the result.
Together, the above four steps are called "learning speculation", which is the operation of what a person has learned and thought in his inner world, or the processing of thinking level. The last step is to express what you think and get in the outside world, and land on the behavior level: persist, implement firmly, and implement firmly. This is the process of practicing learning ambition.
The last step is called "practice". "Learning and thinking, doing", these two stages together, is the unity of knowing and doing, that is, applying what you have learned, which is what Xia Zi, a student who recorded Confucius in The Analects of Confucius, said.