Mencius – Chapter 13.4

Mencius said, “The principles of all things are already complete within myself.
If I examine myself and find that I am truly sincere, there is no greater joy than this.
If I strive to act according to the principle of reciprocity (shu), there is no closer path to seeking benevolence.”

Note

This passage, also from the Jin Xin I chapter of the Mencius, is one of the most transcendent and frequently cited maxims in Mencius’ philosophy of mind and nature, especially by later Neo-Confucian scholars. It marks the Confucian leap from ethical morality to metaphysical ontology. Drawing on traditional commentaries, we can understand its underlying thought through the following dimensions:

• The Ontology of the Unity of Heaven and Humanity: The Inner Completeness of “All Things Are Complete Within Me”
  “All things are complete within me” is the ultimate expression of Mencius’ theory of innate goodness. Mencius believed that the universal laws of the universe (the Way of Heaven) and the inner moral nature of man (the Way of Man) are completely interconnected. The sprouts of benevolence, righteousness, propriety, and wisdom possessed by humans are manifestations of the life-giving principles of all things in the universe. Therefore, one does not need to blindly seek outwardly, because all the potential and moral laws required to become a sage and align with the universe are already perfectly inherent within every person’s mind. This established the philosophical cornerstone of the Confucian “inward search.”
• The Ultimate Joy of Morality: The Realm of “Examining Oneself and Being Sincere”
  Since the principles of all things reside within my mind, where does the ultimate joy of life come from? Mencius’ answer is “examining oneself and being sincere.” “Sincerity” means being genuine and without deceit or self-deception. When a person examines themselves and confirms that their words and actions are entirely consistent with their inner conscience, without any hypocrisy or impure motives, they will experience a profound inner joy that does not depend on any external material conditions (there is no greater joy than this). This “joy” is the spiritual freedom that follows when moral practice reaches a high degree of self-awareness, and it is also the “Joy of Confucius and Yan Hui” pursued by later Neo-Confucianism.
• The Practical Bridge to Benevolence: The Practical Methodology of “Striving to Act with Reciprocity”
  If “all things are complete within me” is a highly elevated ontological realm, how should ordinary people begin their practice? Mencius immediately provided the most grounded practical method: “reciprocity” (shu: do not do unto others what you would not have them do unto you; extending one’s own feelings to others). “Striving” means making a determined effort. Mencius pointed out that although human nature is inherently complete, in reality, it is often obscured by selfish desires. Therefore, one must force oneself to persistently apply the principle of reciprocity in dealing with people and matters. This is the most direct and immediate stepping stone to transforming inner “sincerity” into outer “benevolence.”

孟子曰：“万物皆备于我矣。反身而诚，乐莫大焉。强恕而行，求仁莫近焉。”