The next sentence of "there is specialization in the technical field" is "nothing more", but usually the interpretation of "there is specialization in the technical field" is that there is a sequence of listening to the truth (early and late), and everyone has his own expertise in technical learning. From the theory of teacher Tang Hanyu.

The world said (excerpt) in:

Ancient scholars must have teachers. Teacher, so preach and teach to solve doubts. People are not born knowing, who can have no doubt? If you are confused and don't follow the teacher, you will be confused and you will never understand. Before I was born, I studied Tao before I was born, so I learned from Tao. After I was born, I studied Taoism first, so I studied Taoism. I am a teacher, and I don't know that years were born in me. Therefore, there is no nobility, no inferiority, no length, no shortage, and the existence of Tao and the existence of teachers.

Translation:

People who studied in ancient times must have teachers. A teacher is a person who teaches Taoism, studies and explains difficult problems. People are not born with knowledge and truth. Who can not doubt it? With doubts and not learning from teachers, those problems that become confused will never be solved. Born in front of me, he understood the truth earlier than me, so I (should) follow (him) and regard him as a teacher; Born behind me, (if) he knows the truth before me, I (should) follow (him) as a teacher. The tradition of studying as a teacher, where to consider whether he is older than me or younger than me? Therefore, regardless of status and age, the place where truth exists is the place where teachers exist.

Explain the truth of learning from teachers, satirize the world that is ashamed of being a teacher, educate young people, and play a role in changing the atmosphere. This paper lists positive and negative examples, compares and demonstrates repeatedly, discusses the necessity and principle of learning from teachers, criticizes the bad habit of "being ashamed to learn from teachers" in society at that time, shows extraordinary courage and fighting spirit, and also shows the spirit of the author to express his opinions independently regardless of the secular. Although the full text is not long, it has profound implications, distinct arguments, rigorous structure, thorough reasoning and strong persuasiveness and appeal.