Being a supreme domain in terms of principle, li (理) exists in different things and manifests itself in different forms. “There is but one li, which exists in diverse forms” – this is an important way in which the Song- and Ming-dynasty thinkers viewed the forms in which li exists. As li has different meanings, its one-and- diverse composition is also interpreted in different ways. First, as the origin of universe in an ontological sense, li runs through all things. The li of each thing is not a part of li, rather, it is endowed with the full meaning of li. Second, representing the universal law governing all things, the universal li expresses itself in the form of different guiding principles in specific things. The li of each thing or being is a concrete expression of the universal li. The concept of li being one and same ensures unity of the world, whereas its diversity provides the basis for multifarious things and hierarchical order.

Li (universal principle) runs through all things, which is derived from one source. But as li is present in different things, its functions and forms vary. (Categorized Conversations of Master Zhu Xi)

When a person or thing comes into being and is endowed with qi, or vital force, he or it is governed by only one li (universal principle). However, once a person or thing gains a specific physical form, the li embodied expresses itself in different ways. (Luo Qinshun: Knowledge Painfully Acquired)