Li （理, pinyin
lǐ）is a concept found in
Neo-Confucian Chinese philosophy. It refers to the underlying reason and order of nature as reflected in its organic forms.
It may be translated as "rational
principle" or "law." It was central to
Zhu Xi's integration of
Buddhism into Confucianism. Zhu Xi held that
li, together with
qi (氣: vital, material force), depend on each other to create structures of nature and matter. The sum of
li is the
Taiji.
This idea resembles the
Buddhist notion of
li, which also means "principle." Zhu Xi maintained, however, that his notion is found in
I Ching (
Book of Changes), a classic source of
Chinese philosophy. Zhu Xi's school came to be known as the School of
Li, which is comparable to
rationalism. To an even greater extent than Confucius, Zhu Xi had a naturalistic world-view. His world-view contained two primary ideas: qi and li. Zhu Xi further believed that the conduct of the two of these took places according to Tai Ji.
Holding to Confucius and Mencius' conception of humanity as innately good, Zhu Xi articulated an understanding of li as the basic pattern of the universe, stating that it was understood these principles that one couldn't
live with li and live an exemplary life. In this sense, li according to Zhu Xi is often seen as similar to the Dao in Daoism or to telos in Greek philosophy and also to the Dharma in Hinduism . Wang Yangming, a philosopher who opposed Zhu Xi's ideas, held that li was to be found not in the world but within oneself. Wang Yangming was thus more of an idealist with a different epistemic approach.
