The word 道理 is formed by combining two profound concepts: 道 (dào), which originally means "path" or "way" and extends to the fundamental natural order or the guiding principle of the universe, and 理 (lǐ), which means the inherent pattern, reason, or inner logic of things. Together, they merge to create a composite idea where the grand, cosmic "Way" (道) is given structure and understandable form through its underlying "reason" or "principle" (理), thus arriving at the meaning of a coherent truth, a rational argument, or a justifiable course of action.