‘道理’ (dào lǐ) literally combines ‘dào’ (way, path, principle) and ‘lǐ’ (reason, logic, pattern), together meaning ‘the underlying reason or principle that makes something true, right, or understandable.’ It refers not just to logical explanation but also to moral or natural law — the ‘why’ behind actions, rules, or phenomena. You’ll hear it in discussions about fairness, science, ethics, or everyday decisions.

Unlike simple synonyms like ‘原因’ (yuányīn, ‘cause’), ‘道理’ carries a sense of legitimacy and coherence — something must make sense *and* align with accepted standards. It’s often used in phrases like ‘讲道理’ (jiǎng dào lǐ, ‘to be reasonable’) or ‘有道理’ (yǒu dào lǐ, ‘that makes sense’). While it can appear in formal contexts, it’s equally common in casual speech when evaluating opinions, advice, or behavior.