📖 Meaning
This idiom conveys that a person's inner thoughts, intentions, and true character are extremely difficult to discern or predict. It warns that outward appearances and words can be deceptive, so one should never assume they fully know what another person is really thinking.
📜 Origin Story
The phrase first appears in Sima Qian's Records of the Grand Historian (《史记》), in the biography of Han Xin, the Marquis of Huaiyin, a military strategist of the Western Han dynasty. In recounting how the former kings of Changshan and Cheng'an — who had once been sworn friends as commoners — ultimately turned on and captured each other, the text explains that their downfall arose from excessive desires, concluding: 'Trouble is born of greed, and the human heart is hard to fathom' (患生于多欲，而人心难测也). The saying thus entered the language as a warning about the inscrutability of human motives.
💡 Example Usage
世事无常，人心难测，凡事还是多留个心眼才好。
The world is ever-changing and the human heart is hard to fathom, so it is always wise to stay a bit cautious in everything.
🏷️ Category
➕ Similar Idioms
➖ Opposite Idioms
🔤 Quick Facts
- Chinese: 人心难测
- Pinyin: rén xīn nán cè
- Literal Translation: human heart, difficult to fathom
- Category: Wisdom
- Characters: 4