Xia Zi said, "... a gentleman is respectful and polite to people. All men are brothers within the four seas. Why do gentlemen have no brothers? "

The definition of "four seas" refers to the world and the whole country. It means people all over the world are like brothers.

Sima Niu, a disciple of Confucius, once asked Kong Yu how to be a gentleman. Confucius said to him, "A gentleman is not worried or afraid." Sima Niu didn't understand what this meant and asked, "Are you a gentleman if you are not sad or afraid?" Confucius said: "A gentleman often introspects; So there is no guilt in my heart. What can I be sad and afraid of? " After Sima Niu left Confucius, he met his brother Xia Zi. He was very sad and said, "Everyone has a brother. How happy I am, but I am not. " Xia Zi comforted him and said, "I have heard that' a person's life and death should be arranged by fate, while wealth is arranged by heaven. A gentleman is careful and makes no mistakes; The attitude towards people is respectful and polite. Then there are brothers everywhere in the world, so why should a gentleman worry about not having brothers? "