Tolerance. In Confucius's thought system, "Shu" (Reciprocity/Forgiveness) is a consistent and guiding principle. The Analects, Book Four (Li Ren), states: "Zengzi said, 'Our Master's Way is simply Zhong (Loyalty) and Shu (Reciprocity).'" The Analects, Book Fifteen (Duke Ling of Wei), states: "Zi Gong (a wealthy and eloquent disciple) asked, 'Is there one word that can guide one's entire life?' The Master said, 'Would it not be Shu? What you do not wish for yourself, do not impose on others.'" Thus, Confucius's "Shu" speaks of a virtue unifying self and others, requiring one to put oneself in another's place and refrain from imposing what one dislikes on others. When discussing "Shu," Confucius often linked it with "Zhong" (Loyalty/Devotion). In this context, as Confucius said: "If you wish to establish yourself, help others establish themselves; if you wish to achieve, help others achieve" (The Analects, Book Six, Yong Ye). His meaning is: treat others as you wish to be treated. Thus, "Zhong" complements "Shu"; when linked together, it adds a positive dimension to the otherwise more passive "Shu." Confucius's concept of "Shu," while maintaining personal independence, also demonstrates respect for others' personhood, thus fostering a degree of equality in human relations and granting individuals the freedom of self-choice.
However, this does not mean that Shu (Reciprocity/Consideration) is unconditional. As an important component of Ren (Benevolence), Shu also takes Li (Propriety) as its external form of expression, which determines that it must be premised on the traditional concepts of "respect for superiors" and "affection for kin." The Analects, Book Three (Ba Yi) states: "Serve the ruler with complete Li (Propriety)." The same book, Book One (Xue Er), also states: "When at home, a young person should be Xiao (Filial), and when abroad, Ti (Fraternal)." This inevitably confines Shu, the principle of extending oneself to others, within a limited framework. The Book of Rites, "Doctrine of the Mean" (Zhongyong), quotes Confucius as saying: "Zhong (Loyalty) and Shu (Reciprocity) are not far from the Dao (The Way). Do not impose on others what you yourself do not desire. The Junzi (Exemplary Person) has four ways of conduct, of which I have not been able to fulfill even one. What I require of a son in serving his father, I have not been able to do; what I require of a minister in serving his ruler, I have not been able to do; what I require of a younger brother in serving his elder brother, I have not been able to do; what I require of a friend in treating others, I have not been able to do first." Confucius believed he had not been able to fully practice the "Way of Zhong (Loyalty) and Shu (Reciprocity)." He did not apply the standards he demanded of a son to serve his father, nor the standards he demanded of a minister to serve his ruler, nor the standards he demanded of a younger brother to serve his elder brother, nor did he treat friends as he would expect to be treated. This tells us that the so-called "extending oneself to others" is derived according to one's position in the patriarchal hierarchy, not without any constraints. The Book of Rites, "Great Learning" (Daxue), further develops this idea into the "Way of the Measuring Square" (Xieju zhi Dao): "Do not use what you dislike in your superiors to employ your subordinates; do not use what you dislike in your subordinates to serve your superiors; do not use what you dislike in those before you to precede those after you; do not use what you dislike in those after you to follow those before you; do not use what you dislike on your right to associate with your left; do not use what you dislike on your left to associate with your right." The spirit of Shu (Reciprocity) embodied here is also considered from the perspective of relationships between superiors and inferiors, and left and right. Overall, Confucius's Shu (Reciprocity) primarily required the Junzi (Exemplary Person)—nobles, ministers, and scholar-officials—to extend love for their family to the entire world, while also reminding these individuals to respect and value themselves.