自相矛盾 Zì Xiāng Máo Dùn
There was once a peddler who sold weapons. (The ancient word for “weapons” was máo dùn 矛盾 – which now means “contradict”.) When he arrived in a new town, he would give a performance to attract a crowd, and then proceed to pitch his wares.
“This spear is the best in the world,” he would say. “It can go through anything.”
Then he presented a shield and said, “This shield is made of the finest leather. Nothing can pierce it.”
Someone called out from the crowd, “If you take the spear and shoot it at the shield, what will happen?”
Since that time, a person who contradicts himself is described as zì xiāng máo dùn.
