This sentence was said by Zhang Hengqu, a great scholar in the Northern Song Dynasty. Zhang Zai (1020- 1077), a native of Hengqu Town, Yanxian County, Fengxiang County (now Meixian County, Shaanxi Province), was a thinker, educator and one of the founders of Neo-Confucianism in the Northern Song Dynasty. Known as Mr. Hengqu in the world, Zhang Zi is honored as a saint, and he is thirty-eight in the west of Confucius Temple. His famous saying, "Make a heart for heaven and earth, be a man, link the past with the future, and create peace for all generations", was called "four sentences in a horizontal canal" by contemporary philosopher Feng Youlan. Because of its simplicity and grandeur, it has been praised by people throughout the ages.

These four sentences mean: to establish the heart of life for heaven and earth, to point out a way for the people, to inherit the knowledge that Confucius and Mencius and other sages have not inherited, and to open up the foundation of permanent peace for future generations.

The first sentence is "for heaven and earth". At present, the popular explanation is that heaven and earth are unintentional, people have hearts, and people's hearts are also "the hearts of heaven and earth"; "Keeping a heart of heaven and earth" means developing people's thinking ability and understanding natural things and laws. This is a misunderstanding. First of all, in ancient times, the word "heaven and earth" did not specifically refer to nature. There is a "three talents" universe model about heaven, earth and man in the Confucian classic Yi Zhuan, which shows that the ancients tend to regard heaven, earth and man as a whole. So "heaven and earth" is "between heaven and earth", including not only nature, but also individuals and human society. Zhang Zai also called the "heaven and earth" of social significance "the world". Secondly, Zhang Zai did not deny the existence of "the heart of heaven and earth". "The heart of heaven and earth" is a term in the Book of Changes. Zhang Zai, a famous Yi-ology scholar, thinks that "the heart of heaven and earth is just a creature." Obviously, in the sense that heaven and earth can generate everything, Zhang Zai affirmed that heaven and earth are intentional. The heart of life is inherent in heaven and earth, so there is no need for people to "stand up", otherwise their abilities will be unduly exaggerated. "Building the heart of heaven and earth" is actually to establish a spiritual value system with benevolence, filial piety and other moral ethics as the core for the society. In his book The Cave of Confucian Classics, Zhang Zai focused on the significance and methods of "establishing faith". If you turn a blind eye, your understanding of "Lixin" is easy to be guessed. In Zhang Zai's view, "establishing heart" is also the heart of "establishing righteousness", because justice "can make the world happy", so that "the world" (society) must generally accept moral values such as the principle of benevolence and filial piety. According to these data, the meaning of "making a heart for heaven and earth" is very clear, and its focus is not on epistemology, but on axiology.

The second sentence is "making a living for the people". "Destiny" refers to people, and "destiny" refers to people's fate. This involves the problem of "settling down" that Confucianism has been paying attention to. The history books say that Zhang Zai "enjoyed his life". The "fate" of "making a living for the people" mainly refers to people's fate. It has long been popular in history that people can only resign themselves to fate. However, Zhang Zai believes that as long as people make their own moral efforts, they can control their own destiny in spiritual value and give meaning to life. Therefore, "making a living for the people" means choosing the right destiny direction for the people and establishing the meaning of life.

The third sentence is "a lesson from the past." "Most Holy" refers to the saints in history. The so-called saints in Confucianism actually refer to personality models and spiritual leaders. "Juexue" refers to the interrupted academic tradition. Neo-Confucianism generally believes that the Confucian learning system has been extinct since Mencius and should be restored. Zhang Zai inherited "Juexue", but he did not copy his predecessors, but tried to innovate. There are many contents in his theory that are not contained in the Six Classics and are not stated by the former sanctuary.

The fourth sentence is "open peace for the world". Since Duke Zhou and Confucius, "peace" and "great harmony" have been social and political ideals. In the Northern Song Dynasty, politicians and thinkers represented by Fan Zhongyan and Li Gou all put forward the idea of "harmony". Zhang Zai is not limited to the current "Taiping" order, but looks forward to the "Taiping" inheritance of "eternal life" with a far-reaching vision, which is his outstanding point.

The understanding of "four for one sentence" cannot be separated from the founding background of the early Song Dynasty. The rulers of Zhao and Song Dynasties summed up the experience and lessons of the long-term division of the country and established the national policy of "building the country with Confucianism" in order to rebuild social order. In this policy environment, Neo-Confucianism in the Northern Song Dynasty, represented by Zhang Zai and others, is most concerned with laying an eternal spiritual foundation for the ideal order pursued by Confucianism, rather than understanding the "law of nature".

In a word, "four for one sentence" involves the spiritual value, life significance, academic inheritance and political ideal of society and people. We can translate Zhang Zai's "four for one sentence" into modern Chinese: rebuild the spiritual value for the society, establish the meaning of life for the people, inherit the lost academic system for the former saints, and open up the foundation of peace for all generations.