noun
principle of duality; yin-yang principle
Refers to the fundamental concept in East Asian philosophy that all things consist of opposing yet complementary forces (yin and yang). Often used in discussions of traditional cosmology, divination, and natural order.
陰陽の理に従えば、万物は陰と陽の二つの気から成り立っている。
According to the principle of duality, all things are composed of the two energies of yin and yang.
陰陽道 is the broader practice or way of yin-yang divination and cosmology, whereas 陰陽の理 is the abstract principle itself.
Compound of 陰陽 (onmyō, 'yin and yang') + の (possessive particle) + 理 (ri, 'principle, reason'). The reading おんみょう for 陰陽 is an older go-on reading, often used in traditional contexts.