The Liji, "Record of Rites," is one of the Five Classics that anchor the Confucian canon, standing alongside the Classic of Poetry, the Classic of History, the Classic of Changes and the Spring and Autumn Annals. Unlike a treatise composed with a single argument in mind, it is an assembled collection of shorter texts on ritual and social order, ranging from precise ceremonial instruction, how mourning garments should be cut, how a host should seat guests, how a ruler should conduct court ritual, to essays reflecting more abstractly on what ritual is for and why a well ordered society depends on it rather than on law or force alone.
That range gives the Liji two very different faces at once. Much of it reads as a practical handbook, useful chiefly to specialists in ritual performance for its granular procedural detail. But embedded within the larger compilation are two chapters that later readers lifted out and treated as major standalone philosophical works in their own right: the Da Xue, or Great Learning, on the connection between personal moral cultivation and good governance, and the Zhong Yong, or Doctrine of the Mean, on balance and sincerity as the foundation of a well lived life. Both were eventually promoted into the Four Books, the core curriculum of Confucian education from the Song dynasty onward, giving the Liji the unusual distinction of having supplied two of its own chapters to a separate, later canonical grouping.