When combined, `道理 (dàoli)` becomes a single concept meaning “reason,” “logic,” “sense,” or “principle.” Adding the negative `没 (méi)` in front literally creates “have-no-reason,” which perfectly captures the English meaning of “unreasonable” or “illogical.”
The concept of `道理 (dàoli)` is more than just cold, Western-style logic; it's deeply embedded in the Chinese sense of social and moral order. `道理` implies a correct, reasonable, and often universally accepted principle of how things should work or how people should behave. It's the intersection of logic, fairness, and social propriety. Therefore, accusing something of being `没道理` is a significant claim. It's not merely an intellectual disagreement but often a moral or social one. You're suggesting that an action or statement violates a shared understanding of what is right and just. This contrasts with the English phrase “it's illogical,” which can be a neutral observation about a flaw in a process. `没道理`, on the other hand, almost always carries a tone of complaint, frustration, or accusation. In a dispute, a common tactic is to appeal to reason by asking the other person, “你讲不讲道理?” (Nǐ jiǎng bu jiǎng dàoli?), which means, “Are you going to be reasonable or not?” This frames the argument around a shared cultural value of adhering to what is right and proper.
`没道理` is an extremely common phrase used in informal, everyday situations. Its connotation is almost always negative, expressing some level of dissatisfaction.
The phrase is very versatile but is generally considered informal. In a formal debate or academic paper, one would likely use more specific and nuanced language like `不合逻辑 (bùhé luójí)` (doesn't conform to logic) or `荒谬 (huāngmiù)` (absurd).