革故鼎新

Origin and story

The Za Gua commentary to the Book of Changes explains two hexagrams together: Ge removes what is old, and Ding takes up what is new. The later idiom compresses those paired explanations. Ge and Ding are therefore not characters in an origin story; they are names within the text's system of hexagrams.

Their combination joins two sides of renewal: discarding an existing arrangement and establishing a replacement. The phrase has often been used of political or institutional reform, but it can also describe renewal in culture, methods, or an organization. Its emphasis is substantial change, not merely making an old surface look newer.