不得而知

1. Basic Information

• Pinyin: bù dé ér zhī
• English Translation: Unable to find out (impossible to know)
• Idiom Composition: 「不」（Not; a negation.）＋「得」（To be able to; to obtain the possibility of doing something.）＋「而」（A conjunction used here to connect the possibility to the action.）＋「知」（To know; to understand; to find out.）
• Meaning: To be unable to know or ascertain something because the information is unavailable or there are no means to find out. It describes an objective state where the truth remains unknown.

2. Detailed Meaning and Nuances

「不得而知」 contains the following nuances:

• Emphasis on Impossibility: By using the character 得 (dé), which means 'to be able to,' the idiom emphasizes that it is not just a matter of personal ignorance, but that there is no way or means to obtain the knowledge.
• Objective Description: While it can be used to describe personal lack of knowledge, it is most often used in news or essays to state that 'the truth is hidden' or 'the facts are not available' as an objective reality.

3. Usage

「不得而知」 is mainly used in the following contexts:

• Unknown Truths or Causes: Used to describe situations where motives, specific details, or the truth of an event cannot be confirmed. This is common in journalism and investigative reports.
  • Example:「至于他为什么突然辞职，具体原因我们不得而知。」
    （As for why he suddenly resigned, the specific reasons remain unknown to us.）
• Historical Facts: Used when historical records are missing or unclear, making it impossible to verify past events.
  • Example:「这座古庙建于哪个朝代，现在已经不得而知了。」
    （Which dynasty this ancient temple was built in is impossible to know now.）
• Withholding Judgment: Used as a formal way to say 'it remains to be seen' or 'it is uncertain,' often to avoid making a definitive claim.
  • Example:「这个计划能否成功不得而知，但我们必须试一试。」
    （Whether this plan will succeed remains to be seen, but we must try.）

Additional Examples:

1. 凶手作案的动机至今仍不得而知。
   （The killer's motive for the crime remains unknown to this day.）
2. 他们两人之间到底发生了什么，外人不得而知。
   （What exactly happened between the two of them is impossible for outsiders to know.）
3. 这幅画的作者是谁，目前还不得而知。
   （Who the artist of this painting is remains a mystery for now.）
4. 虽然传闻很多，但真相如何不得而知。
   （Although there are many rumors, the actual truth cannot be ascertained.）
5. 他去向如何，我们都不得而知。
   （None of us can know where he has gone.）

4. Cultural Background and Notes

• Formal Register: Compared to the colloquial 不知道 (bù zhī dào), 不得而知 (bù dé ér zhī) is a more sophisticated expression preferred in written Chinese (书面语 - shū miàn yǔ) and formal speeches.
• Classical Structure: The idiom retains the grammatical structure of Classical Chinese (文言文 - wén yán wén), where the character 而 (ér) serves as a bridge between the potential (不得) and the action (知).
• Common Contexts: It is a staple phrase in documentaries, academic papers, and investigative journalism when discussing 'unsolved mysteries' or 'unconfirmed reports.'

5. Similar and Opposite Idioms

• Similar Idioms:
  • 一无所知 (yī wú suǒ zhī): To know absolutely nothing; to be completely in the dark.link
  • 不知所以 (bù zhī suǒ yǐ): Not knowing the why or wherefore; to be at a loss or confused about the reason.
  • 不为人知 (bù wéi rén zhī): Not known by others.link
• Opposite Idioms:
  • 了如指掌 (liǎo rú zhǐ zhǎng): To know something like the back of one's hand (literally: as clear as pointing to one's own palm).
  • 洞若观火 (dòng ruò guān huǒ): To see things as clearly as looking at a fire; to have keen insight and a thorough understanding.
  • 众所周知 (zhòng suǒ zhōu zhī): As everyone knows.link
  • 显而易见 (xiǎn ér yì jiàn): It is obvious and easy to see.link

6. Summary

不得而知 (bù dé ér zhī) is a formal idiom used to express that a fact, reason, or outcome is currently unknown or impossible to verify. While the common phrase 不知道 (bù zhī dào) simply means "I don't know," 不得而知 (bù dé ér zhī) carries a more objective and formal tone, implying that the information itself is inaccessible. It is frequently used in news reporting, historical research, and formal discussions regarding mysteries or unconfirmed details.