想当然 | take for granted or assume without evidence

xiǎng想dāng当rán然

To take for granted; to assume something without evidence or proper investigation; to jump to conclusions based on subjective judgment.

他只是听了一面之词，就想当然地认为这件事的责任都在对方。

He only heard one side of the story and then took it for granted that the other party was entirely responsible for the matter.

Era:

Ancient

Frequency:

Synonym:

想当然耳

Story:

In 203 AD, Cao Cao, accompanied by his son Cao Pi, captured Ye City, the stronghold of Yuan Shao. The 18-year-old Cao Pi, upon seeing Zhen Shi, the 23-year-old wife of Yuan Shang, was captivated by her beauty and forcibly took her as his夫人 (wife).

When Kong Rong learned of this, he wrote a letter to Cao Cao, citing an ancient anecdote: King Wu of Zhou, after defeating King Zhou of Shang, awarded King Zhou's favored concubine, Daji, to the Duke of Zhou. Cao Cao was puzzled by this reference, as it didn't seem historically accurate.

Kong Rong then replied that he was merely 'imagining the past based on the present' (以今度之，想当然耳), implying that he was making an assumption based on what he perceived as a similar situation, rather than actual historical fact.

This phrase '想当然' (xiǎng dàng rán) originated from Kong Rong's response, highlighting the act of making subjective assumptions.

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