Confucius himself anticipates the objection li most readily invites, that ritual can decay into empty formality performed without the feeling it exists to express, and the Analects records him asking rhetorically whether ritual means merely jade and silk, the material tokens of ceremony, insisting the forms are worthless without the reverence, jing, they are meant to carry, a warning against exactly the hollow ritualism critics of Confucianism, ancient and modern alike, have accused the tradition of encouraging.
Peter Bol's history of the Confucian tradition traces a recurring internal debate along these lines across the centuries, Song and later Neo-Confucian thinkers repeatedly reasserting that li without the inward substance of ren is not the virtue itself but only its husk, a corrective aimed at court and gentry practice they judged had drifted toward exactly the hollow observance Confucius warned against.
The Mencius extends li in a further direction, treating the specific capacity for deference and yielding, a disposition to defer to elders and superiors appropriately, as one of the four innate moral sprouts every person is born with alongside compassion, shame and the sense of right and wrong, arguing that li, like ren, has a natural root in human feeling that education and ritual practice are meant to cultivate and extend rather than impose from entirely outside.