In Mencius’ thought, *yi* (義) names the dimension of righteousness or moral rightness at the heart of human nature. It is not merely external conformity to rules, but an inner orientation toward what is fitting, just, and appropriate in a given situation. As one of the fundamental virtues, it stands alongside *ren* (benevolence), *li* (propriety or ritual), and *zhi* (wisdom), forming a core structure of moral life. In this sense, *yi* expresses the conviction that human beings possess an inherent moral capacity, rather than needing to import morality from outside.

This virtue is described as an innate moral sense, rooted in the heart-mind (*xin*), that allows a person to distinguish right from wrong and to feel shame or aversion in the face of what is base or dishonorable. It manifests as a spontaneous, intuitive response: a direct recognition of what ought to be done, even before deliberate calculation or instruction. Such responsiveness reveals itself especially when moral rightness conflicts with personal advantage, for *yi* consistently sides with what is just rather than what is merely profitable. In this way, it stands in deliberate contrast to self-interest, orienting the noble person toward action that may involve sacrifice or risk.

At the same time, *yi* is not a rigid code but a capacity to discern what is morally appropriate within concrete and often complex circumstances. It functions as a kind of inner compass that guides how benevolence is to be expressed, shaping when, to whom, and in what manner care and concern should be directed. This gives *yi* both a deeply personal and a social dimension: it governs the conduct of individuals, yet also orders relationships within family, community, and political life. Through this virtue, ethical behavior becomes attuned to context without losing its grounding in principled rightness.

Although inborn, *yi* does not automatically reach full maturity; it must be cultivated through reflection, practice, and moral education. When nurtured, the initial “sprout” of righteousness can grow into a stable disposition that consistently guides action. This cultivated *yi* reveals the underlying goodness of human nature, showing that the capacity for just and principled conduct is already present, awaiting development. In Mencian terms, to live by *yi* is to allow this native sense of righteousness to become fully operative, so that one’s life aligns with what is morally fitting rather than with the pursuit of gain.