Ning Wuzi (甯武子) was a minister in the state of Wei during the reign of Duke Cheng (衛成公), who ascended the throne in 634 BC. After the Duke was overthrown, he kept his head down by acted dumb while secretly working to engineer his return to power.
Appearances in the Analects of Confucius
Book 5, Chapter XXI
Confucius said: “When the Way prevailed in his state, Ning Wuzi acted wise. When his state lost the Way, Ning Wuzi acted dumb. Others may match his wisdom but not his dumbness.”