自相矛盾 (Zì xiāng máo dùn)

Basic Info

Chinese Idiom: 自相矛盾 (Zì xiāng máo dùn)
Pinyin: zì xiāng máo dùn
Literal meaning: “Self-contradicting spear and shield.”
(自 = self; 相 = mutually / toward each other; 矛 = spear / lance; 盾 = shield)

Figurative Definition

It describes speech or behavior that contradicts itself – saying one thing and then saying the opposite, or making claims that cannot both be true at the same time. It is used to criticize logical inconsistency, hypocrisy, or statements that cancel each other out. In short: to contradict oneself.

Cultural & Historical Origin

This famous story comes from the Legalist classic Han Feizi (《韩非子》), in the chapter 36 “Difficulties of Persuasion, Part One” (难一).

A man from the state of Chu was selling both spears and shields at the market. He boasted about his shields:

“My shields are so strong that nothing can pierce them!”

Then he boasted about his spears:

“My spears are so sharp that they can pierce anything!”

A bystander asked him:

“What if I take your spear and try to pierce your shield – what happens then?”

The man could not answer. If his shield could stop anything, his spear could not pierce it. If his spear could pierce anything, his shield could not stop it. Both claims could not be true at the same time.

From this story, the idiom “自相矛盾” was born – and the Chinese word for “contradiction” (矛盾) literally comes from “spear and shield.”

Key Lesson

Think before you speak – and make sure your claims are consistent. If your words contradict each other, you will lose credibility and be easily refuted. The story also teaches the importance of logical thinking: a statement that cannot survive a simple counter-question is not a valid argument.

Cultural Note

This is one of the most famous stories in Chinese philosophy, and the word “矛盾” (máo dùn) is now the standard Chinese term for “contradiction” – used in everyday speech, philosophy, and even Marxist dialectics (where “矛盾” means “contradiction” in a philosophical sense).

The idiom “自相矛盾” is widely used to criticize:

• Politicians who say one thing and do another.
• Advertisements that make impossible claims.
• Arguments that collapse under their own logic.
• People who change their story to fit the moment.

Similar English Expressions

• To contradict oneself – The most direct equivalent.
• Self-contradictory – Describing a statement that cannot be true.
• To be hoist with one’s own petard – To be caught in one’s own trap or argument.
• To talk out of both sides of one’s mouth – To say different things to different people.
• To blow hot and cold – To keep changing one’s position.
• A double bind – A situation with contradictory demands (different nuance).
• To tie oneself in knots – To become hopelessly confused by one’s own logic.
• A catch-22 – A contradictory situation with no good outcome (different nuance).

The closest and most natural equivalent is “to contradict oneself” or “self-contradictory.” English speakers also immediately understand the image of “spear and shield” when explained.