Li and Qi: Principle and Vital Force

Li is the principle, pattern, or reason inherent in all things — the normative structure that makes each thing what it is and that, in human beings, constitutes moral nature. Qi is the vital force or psychophysical stuff through which li is instantiated and actualised: without qi, li is not yet embodied; without li, qi has no direction or form. All things in the world consist of li and qi together, but the two are conceptually distinct. Li is prior in the order of principle (though not necessarily in the order of time); qi is the medium through which li is expressed, and because qi varies — it can be clear or turbid, concentrated or diffuse — the same li can be expressed well or poorly in different individuals and situations.

The orthodox Zhu Xi position was that li has no activity, will, or capacity for action — it is purely formal. Qi does all the moving and manifesting. Yi Hwang, however, argued that li has its own dynamism (sadansil li chi bal): in the Four Beginnings — the moral sprouts of humanity, righteousness, ritual propriety, and wisdom — it is li itself that issues forth. The Seven Emotions — joy, anger, sorrow, fear, love, dislike, desire — are issuings of qi. This is the core of the Four-Seven thesis that Yi Hwang developed against Ki Taesung in their famous exchange (1559–1566). The claim that li is not entirely passive was controversial but gave moral cultivation a firmer ontological basis: virtue is not merely the result of the correct deployment of psychophysical energy but the realisation of an inherently active moral principle.

If li is active and issues forth in the Four Beginnings, then moral cultivation is not simply a matter of controlling the physical passions (qi) but of allowing the moral nature (li) to express itself without obstruction. The task of the sage learner is to maintain the conditions — reverence, tranquillity, sustained attention — in which li can manifest clearly. Turbid or agitated qi blocks the expression of li; clarified qi allows it through. This is why Yi Hwang emphasises the twin practice of reverence (kyŏng) and righteousness (ŭi) — the former maintaining inner composure that keeps the channel of li open, the latter expressing li in action.

Yi Hwang's li-qi theory is most fully developed in the Four-Seven Debate with Ki Taesung, conducted by letter between 1559 and 1566. The positions of both philosophers are collected and translated in The Four-Seven Debate (Michael Kalton et al., 1994). The Ten Diagrams on Sage Learning (1568) presents a more compressed and pedagogically organised version of the same framework.