The characters literally combine to mean “to clean one's body and value oneself.” Metaphorically, this means to keep one's character pure and to cherish one's own integrity and reputation above all. The key is understanding `好 (hào)` as an active verb of “valuing” or “cherishing,” which gives the idiom its sense of proactive self-discipline.
洁身自好 is a concept deeply embedded in Chinese culture, heavily influenced by Confucian ideals. It reflects the value placed on the `君子 (jūnzǐ)`, the ideal “gentleman” or “noble person,” who cultivates their personal virtue regardless of the chaos or corruption of the world around them. It is the individual's responsibility to maintain their moral compass. A useful Western comparison is the phrase “to keep your nose clean.” However, there's a key difference in motivation. “Keeping your nose clean” is often pragmatic—it's about avoiding trouble, staying out of jail, or not getting fired. 洁身自好, on the other hand, is more philosophical and internal. It's about protecting one's honor and inner purity for its own sake, because integrity is an essential part of one's identity. It's less about avoiding punishment and more about upholding virtue. This idiom is tied to core Chinese cultural values like self-discipline (`自律, zìlǜ`), personal integrity (`正直, zhèngzhí`), and the importance of reputation or “face” (`面子, miànzi`). To lose one's integrity is to lose face not just for oneself, but for one's family.
洁身自好 is a formal idiom, most often found in writing, news reports, serious discussions, or when giving advice.
While overwhelmingly positive, it can occasionally carry a subtle, slightly negative connotation of being aloof or “holier-than-thou.” Someone who is too focused on 洁身自好 might be seen as unwilling to get their hands dirty or help with a messy but necessary situation.